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The first-generation Porsche Cayenne was equipped with a range of engine options over its seven-year production run from 2003 to 2010. These are most easily split into early Porsche 955 Cayenne port-injected engines sold from 2003 to 2006, and late Porsche 957 Cayenne direct-injected engines sold from 2008 to 2010. Both the 955 and 957 feature naturally aspirated VR6, V8, and twin-turbo V8 options depending on the model and the trim level. This article will break down the specifications for each engine, common problems, and best practices for servicing and maximizing engine life. 

First-Generation Porsche Cayenne Buyer's Guide

First-Generation Porsche Cayenne Transmissions Guide

 

Porsche Cayenne 955/957 Engines Guide Sections

Porsche 955 Cayenne

Porsche 957 Cayenne

 

 

One of the best ways to make your Porsche Cayenne ownership experience as affordable and easy on the wallet as possible is to do as much of your own service as possible. Porsche dealerships and independent specialists will typically have higher labor rates compared to many other European makes, resulting in substantial savings if you can tackle a lot of the smaller problems and services yourself. 

01_Porsche 957 Cayenne S driveline diagram

Additionally, most of the major issues seen on the different 955 and 957 Cayenne engines has to do with the extended oil service intervals recommended by Porsche. Porsche recommends 20,000-mile service intervals for all V8 models and 10,000-mile service intervals on all VR6 models. Both of these numbers are far too high based on the sort of driving conditions we see in the USA, along with the increase in harmful contaminants absorbed by the ethanol in the vast majority of our pump fuels. Shorter 5,000-mile engine oil services will go a long way to preventing many preeminent Cayenne engine problems. 

01.5_Porsche Cayenne Engine oil service kit

Using the correct Porsche Cayenne coolant is also important, as it is not able to be mixed with other common coolants and antifreeze brands found in auto parts stores. Modern water-cooled Porsches like the Cayenne use the same specification as Volkswagen G12/G13 coolant. This coolant is easily identifiable by its pinkish/purple color, and all variations of G12, G12+, and G13 are compatible with each other. 

 

Porsche 955 Cayenne 4.5 L NA V8 (Engine Code: M48.00)

02_Porsche 955 Cayenne S Engine bay

The M48.00 is a naturally aspirated aluminum block and head V8 engine that came in all 955 Cayenne S models sold between 2003-2006. Featuring dry-sump lubrication, variable intake valve timing, and an oversquare design for maximum horsepower, this dual-overhead-cam engine features a relatively simple and durable timing chain system and is generally considered to be a reliable engine. A Porsche VarioRam dual-plenum intake manifold works to boost low-end torque, an important factor for a 5,000lb truck with a 7,716lb towing capacity. There are some common problems to be aware of, but for the most part, these engines can last many thousands of miles with the proper care and maintenance. If you’re looking to purchase a 955 Cayenne, this will be one of the most common engines under the hood. 

Technical Specifications:

  • Engine code: M48.00
  • Years: 2003-2006 
  • Models: Porsche Cayenne S
  • Engine type: Naturally Aspirated 90-degree V8, aluminum block and heads, DOHC, 4-valves per cylinder, Porsche VarioRam dual-plenum intake manifold, Porsche VarioCam variable valve timing, dry sump lubrication
  • Displacement: 4.5 L (93mm bore x 83mm stroke)
  • Power output: 335hp/310lb-ft of torque

 

Porsche 955 Cayenne 4.5 L Twin Turbo V8 (Engine Code: M48.50/M48.50S)

03_Porsche 955 Cayenne Turbo Engine bay

The M48.50 is the twin-turbo variant of the naturally aspirated Cayenne S M48.00 engine. For the most part, these engines are effectively identical and utilize many of the same components. Still, several changes are made to the M48.50 Turbo that increase power and make it more durable.

First, the M48.50 uses an Alusil block rather than Lokasil-coated cylinder walls. We discuss this in-depth a bit later on, but the Alusil casting process has generally seemed to produce more durable cylinder walls than the Lokasil process. Aside from the obvious addition of two turbochargers, the Turbo engine features forged pistons and piston oil squirters in the block that aid in lubrication and piston cooling. Porsche also does away with their VarioRam intake system as the turbos allow for a much higher torque output without the need for the dual-plenum intake manifold. Most of the common problems on the Porsche 955 Cayenne Turbo are the same as those seen on the 955 Cayenne S.

Technical Specifications:

  • Engine code: M48.50/M48.50S
  • Years: 2003-2006
  • Models: Porsche Cayenne Turbo, Cayenne Turbo S
  • Engine type: Twin-turbocharged 90-degree V8, aluminum block and heads, DOHC, 4-valves per cylinder, Porsche VarioCam variable valve timing, dry sump lubrication
  • Displacement: 4.5 L (93mm bore x 83mm stroke)
  • Power output: 444hp/457 lb-ft of torque (Turbo) - 514hp/531lb-ft of torque (Turbo S)
  • Oil Capacity: 

 

Porsche 955 Cayenne 4.5 L NA/Twin Turbo V8 Engine Problems

The most common problems found with the 4.5 L Cayenne S and Cayenne Turbo are related to the cooling system and ignition system, although there are other areas of concern. Most of the common problems are relatively minor and can be repaired without major expense, but some issues can be more serious, such as cylinder bore scoring.  

 

Coolant pipes 

03.1_Porsche Cayennecoolant pipe repair diagram

If you have a Porsche Cayenne coolant leak and have the 4.5 L M48.00/M48.50 engine, it is often the coolant pipes that have cracked or failed. These are made from a composite plastic material and run under the intake manifold in the valley pan of the engine and are known to crack and leak over time. It’s such a common problem that Porsche lost a class-action lawsuit related to the plastic coolant pipes. There is an updated aluminum pipe kit available that will prevent the coolant pipes from leaking again, so you only have to do this repair once. They can also leak for some time before there is a major or obvious failure, causing other residual issues with the starter motor and torque converter seal. 

Common symptoms of leaking Cayenne coolant pipes include a strong smell of coolant, low coolant level in the expansion tank, or if you see coolant leaking from underneath the intake manifold on either the front or backside of the engine. Sometimes this will be visible more towards the middle of the car as it runs down the transmission and off onto the ground. 

 

Starter motor

The Cayenne’s starter motor can be damaged by leaking coolant pipes. The starter motor is located directly under the coolant pipes, and depending on how long the coolant pipes have been leaking and how much visible coolant residue is on the starter, it’s often a good idea to proactively replace the starter motor as a preventative service. 

A bad starter motor will struggle to start the engine or fail to engage the flywheel when you start your Cayenne. Usually, that will result in a very loud “clicking” noise, similar to when your battery is low on voltage but not totally flat. 

 

Water pump/thermostat

Water pump replacement will be a fact of life on any engine no matter the brand, make, or model. If the Cayenne’s water pump fails completely, it can result in overheating due to lack of coolant flow, or the impeller can make contact with the block and begin to cause damage. With an aluminum block and head engine such as the M48.00/M48.50, you will want to avoid overheating at all costs, as only a small amount of time overheating can cause head gasket, block, and head issues. The thermostat assembly can also fail, causing the thermostat to either stick open or closed.

The first symptom of a failing water pump is typically a small leak. You will first notice the smell of coolant, and then typically, once it begins to worsen, you will notice a low coolant level in your expansion tank, and you’ll be able to see the coolant leaking down the front of the engine block. In an extreme case, coolant may get on the accessory drive belt and cause slipping, and it will spray coolant around the engine bay. 

Symptoms of a bad thermostat include either overheating due to a thermostat that is stuck closed, or an engine that is slow to warm up or never reaches operating temperature due to a thermostat that is stuck open. In either situation, you will likely get some kind of engine code for a performance malfunction or mechanical failure in the cooling system along with a check engine light.

Because the Porsche 955 Cayenne coolant pipes and thermostat assembly are all connected and part of the same system, it’s a good idea to replace the coolant pipes, thermostat, and water pump all at once. This keeps you from having to remove the intake manifold twice for related jobs, saves on having to use more coolant, and ensures that all your major cooling system components are fresh. With all that done, you’ll be good to go for another 80-100,000 miles, and you won’t have to worry about it. 

 

Ignition coils

The M48.00 4.5 L NA V8 and M48.50 4.5 L Turbo V8 Cayenne feature individual ignition coils on each spark plug. Over time these can fail, mainly due to the extreme heat they have to deal with. A bad ignition coil will usually cause an engine misfire. If you continue to drive your Cayenne with a misfire, it can contribute to the biggest issue for the 4.5 L V8, or any aluminum Cayenne engine: cylinder bore scoring. This is because the unburned fuel will wash the engine oil from the cylinder walls, causing an increase in friction and wear between the piston and the cylinder wall. 

There are several obvious symptoms of a failing ignition coil. There will be a rough idle, loss of power, and a check engine light along with fault codes for cylinder misfires. A flashing check engine light is always a sign to immediately stop driving the car to avoid serious engine damage. 

We typically recommend replacing ignition coils as complete sets, but by using an engine scan tool, you will be able to determine which individual cylinder is misfiring and replace that single ignition coil if you prefer. Since this is such a simple repair, carrying a couple of extra ignition coils in your spare parts bag will ensure you never get stranded due to a bad ignition coil. 

 

Cylinder bore scoring

Porsche Cayenne cylinder bore scoring is by far the most serious engine issue that you will see on the 955 4.5 L M48.00 and M48.50 V8 engines. Although this issue can happen on any engine and is more likely to happen on an aluminum block engine, the 955 Cayenne S seems to suffer from it more than any other first-generation Cayenne model. There are a few thoughts as to why this is the case, but the primary cause seems to be from lack of regular oil service and the slightly less durable Lokasil aluminum cylinder wall coating used on the NA M48.00, compared to the Alusil block used on the M48.50 Cayenne Turbo. 

Both Lokasil and Alusil are a patented production process that is designed to create a durable cylinder bore surface in an aluminum block engine. In the Lokasil process, a ‘sacrificial’ cylinder bore liner made of high-content silicone fibers is inserted into the engine mold during the casting process. The liner burns away, and the cylinder bore is left with the high content of silicone bonded to the cylinder bore surface, protecting the softer aluminum block from wear. In an Alusil block, the entire engine block is made of a high-silica content aluminum alloy. After being machined, the block is dipped into an acid bath that burns away all of the lighter materials at the surfaces, leaving only the hardened high-silicone surface behind. Theories suggest that the coating process itself, base engine block materials, and the size of the cylinder lining particles all factor into the coating's durability. Whatever the specifics, it does appear that Lokasil blocks may be more susceptible to bore scoring, but it can happen to any aluminum block engine relying on a hardened or coated cylinder bore. 

There is some anecdotal evidence suggesting that cylinder wall bore scoring is more common on cold-climate Cayennes or those that sit for long periods of time. The Turbo Cayenne M48.50 has piston oil squirters that increase oil lubrication and aid in piston cooling, including at cold start. Since the 955 Cayenne Turbo is typically known as being less-susceptible to cylinder bore scoring, this suggests a lack of oil lubrication during cold start is at least partially responsible for damage. Aside from keeping your Cayenne 955 up to date with the best quality Porsche-approved A40 spec engine oil and engine oil filter, using a proven anti-friction additive such as LIQUI MOLY Ceratec or MoS2 will help to ensure maximum lubrication and protection even in low or zero oil pressure situations. We usually recommend using Ceratec every 4th oil change and utilizing MoS2 on the changes in between. 

The most common symptoms of cylinder bore scoring include oil consumption, engine misfires, and a lack of power. Engines with severely damaged cylinder bores will have a loud knock at idle. If your Cayenne S develops cylinder bore scoring, there are no easy or effective means to repair the engine, as the block itself is damaged. The most cost-effective option is to replace it with a known-good used engine. Pricing can vary quite a bit but expect to pay at least $1,500 to $2,500 for a 4.5 L M48.00 Cayenne S engine. The Turbo variants are less common and tend to demand higher prices. 

 

Coolant return ‘T’ hose fitting (M48.50/M48.50S Turbo only)

This is a simple plastic ‘T’ fitting that can break, causing a major coolant leak. This T junction is not available alone, and you need to purchase the Porsche 955 Turbo Cayenne return hose to replace the faulty part, but thankfully it’s not that expensive. The best practice is to replace your coolant return hose that contains this T when you do your coolant pipes, or at every water pump service just to be safe, around every 80-100,000 miles. 

If your coolant return hose T fitting fails, you will have a massive, immediate coolant leak. 

 

Coolant expansion tank

It’s common for the coolant expansion tank to crack and leak on all engine variants of the 955 Cayenne. 

When your coolant expansion tank fails, it will begin to leak. This will produce a noticeable smell of coolant and an obvious loss of coolant, usually visible near or around the front passenger side of the engine bay or tire. Once the coolant falls to a low enough level, you’ll get a low-coolant warning on your dash. 

 

Valve cover gaskets

Over time the valve cover gaskets on your V8 Porsche Cayenne will become brittle and begin to leak. Replacement is fairly easy, and the parts are inexpensive. If your 955 4.5 L V8 Cayenne has over 60,000 miles, it’s a good idea to periodically inspect for leaks at the valve covers, usually when you’re changing your oil. 

Pay attention to the smell of burning oil and look for oil collecting on the bottom sides of the cylinder valve covers as a sign your valve cover gaskets are leaking. Typically this starts with a small amount of oil seepage before it becomes a major leak. You may also find oil in the ignition coil spark plug holes, which is another sign that your valve cover gaskets need to be replaced. 

 

In-tank fuel pumps

The Porsche 955 Cayenne has a saddle-style fuel tank with low-pressure in-tank fuel pumps on both the left and right sides. It’s typically best to replace these as pairs as once one pump goes bad, the other will often not be too far behind it. When replacing these fuel pumps, it is crucial to have as low a fuel level as possible. If the tank is nearly full, you will need to drain it before performing the service. 

Symptoms of bad in-tank fuel pumps include a loss of engine power, stumbling, stalling, being slow to start, or not starting at all.

 

Porsche 955 Cayenne S/Cayenne Turbo 4.5 L V8 Maintenance Recommendations 

 


 

Porsche 957 Cayenne 4.8 L NA V8 (Engine Code: M4801)

04_Porsche 957 cayenne GTS 4.8 V8 Engine Bay

The M4801 is an evolution of the original 4.5 L engine, featuring a larger 96mm cylinder bore for an increase to 4.8 L of displacement. While the core design is the same, there are many changes, including a switch to direct fuel injection, increasing horsepower and fuel efficiency. The troublesome coolant pipe design has been changed, and although the newer 4.8 L design is better, it still has some coolant-related concerns to be aware of. The 4.8 L M4801 is used in the 2008 to 2010 Porsche Cayenne S, with a higher-output variant used in the GTS and Cayenne S Transsyberia. The M4801 carries over all of the previous features, including dry-sump lubrication, aluminum block and head, and a Porsche VarioRam intake manifold, and adds VarioCam Plus variable valve timing with variable valve lift. While the move to direct-injection adds some complexity and cost, the M4801 is generally considered an improvement in all regards compared to the M48.00. Due to a change in cylinder block materials and coatings, the M4801 does not have the same major concerns regarding cylinder bore scoring as the earlier 4.5 L V8. 

Technical Specifications:

  • Engine code: M4801
  • Years: 2008-2010
  • Models: Porsche Cayenne S, Cayenne GTS, Cayenne S Transsyberia
  • Engine type: Naturally Aspirated 90-degree V8, aluminum block and heads, DOHC, 4-valves per cylinder, Porsche VarioRam dual-plenum intake manifold, Porsche VarioCam Plus variable valve timing and valve lift, dry sump lubrication
  • Displacement: 4.8 L (96mm bore x 83mm stroke)
  • Power: 380hp/369lb-ft of torque (Cayenne S) / 399hp/369lb-ft of torque (GTS/Transsyberia)

 

Porsche 957 Cayenne 4.8 L Twin-Turbo V8 (Engine Code: M4851/M4851S)

05_Porsche 957 Cayenne Turbo Engine DIagram

Following in the footsteps of the M48.50, the M4851 is the turbocharged version of the Porsche M4801 4.8 L V8 engine and is used in the 957 Cayenne Turbo, and Turbo S. Utilizing all the same core components and improvements as the NA 4.8 L engine, including direct injection, the M4851 features a big bump in power, with now over 500lb-ft of torque in standard Cayenne Turbo trim. Like the previous Cayenne Turbo, the Turbo 957 4.8 L engine shares more or less the same common problems as its less-powerful naturally-aspirated brother. Like the M48.50, the M4851 does away with the Porsche VarioRam intake manifold, instead relying on boost pressure from the twin turbochargers to make massive amounts of torque. 

Technical Specifications:

  • Engine code: M4851/M4851S
  • Years: 2008-2010
  • Models: Porsche Turbo, Turbo S
  • Engine type: Naturally Aspirated 90-degree V8, aluminum block and heads, DOHC, 4-valves per cylinder, Porsche VarioCam Plus variable valve timing and valve lift, dry sump lubrication
  • Displacement: 4.8 L (96mm bore x 83mm stroke)
  • Power: 493hp/516lb-ft of torque (Cayenne Turbo) / 542hp/553lb-ft of torque (Turbo S)

 

Porsche 957 Cayenne 4.8 L NA/Twin Turbo V8 Engine Problems

While Porsche sorted out the major coolant pipe issues that plagued the 4.5 L V8 Cayenne engines, there are still some issues with the newer design, although they are not as common. With the addition of direct injection, there are some failures associated with that new high-pressure fuel pump, as well as some of the other accessory components, but the engine itself is not as known for major issues when properly maintained, such as the cylinder bore scoring issue. 

 

Air/oil separator

05.1_Porsche Cayenne 4.8 V8 PCV repair diagram

Also known as the PCV valve, the air/oil separator diaphragm is located in the driver’s side valve cover and can fail, creating a number of issues. The valve is integral to the valve cover and is not considered serviceable by Porsche. Thankfully replacement valve covers are not too expensive on the M4801/M4851. The NA and Turbo variants do use different designs, with the NA 4.8 L V8 having a single port and Turbo having a dual-port connection

The air/oil separator failure symptoms include rough running at idle, visible oil smoke from the tailpipe, check engine light, stored fault codes likely for a lean run condition, and oil consumption issues. 

 

Ignition coils

Just as on the 4.5 L engines, the 4.8 L Cayenne’s engine ignition coils can go bad and cause an engine misfire. Replacing them is straightforward. We typically recommend replacing ignition coils as complete sets, but by using an engine scan tool, you will be able to determine which individual cylinder is misfiring and replace that single ignition coil if you prefer. Since this is such a simple repair, carrying a couple of extra ignition coils in your spare parts bag will ensure you never get stranded due to a bad ignition coil. 

You’ll know you have an engine misfire because your Cayenne will develop a rough idle, may have a loss of power, and a flashing or solid illuminated check engine light along with stored misfire fault codes in the PCM. A flashing check engine light is always a sign to immediately stop driving the car to avoid serious engine damage. 

 

Coolant leak at rear cylinder head crossover pipe

Porsche fixed one problem and created another with the 4.8 L coolant pipe design. This is not as common as the 4.5 coolant pipe issue but can be just as much of a pain to repair, if not more so. Basically, the coolant crossover pipe that runs between the two cylinder heads at the back of the engine has a bonded (glued) hose barb that can loosen due to adhesive deterioration. Porsche says this is because of inconsistent amounts of the adhesive being used during assembly, so not all 4.8 L V8 engines will suffer from this problem. An updated Cayenne coolant crossover pipe with a threaded barb is available from Porsche, but it is not an easy install because the engine must be partially removed in order to access it from the backside. Some owners have had success gaining access to the pipe by removing the intake manifold, cleaning all the surfaces, and using the updated Loctite adhesive to re-secure the barb. This is a somewhat similar problem to the Mezger-type coolant pipe failures, as seen on the 996 and 997 911 Turbo, GT2, and GT3 models.

If the barb comes loose, it causes an instantaneous, massive coolant leak at the back of the engine. When this happens, it results in a total loss of coolant, so you will need to be towed home to make the repair. 

 

Coolant valley pipe

Although this plastic pipe is not as failure-prone as the valley pipes on the 4.5 L, Porsche is still using plastic in a relatively hard to access area. This pipe runs from near the coolant crossover pipe barb, under the intake manifold, to the engine coolant thermostat housing. There is an updated aluminum version, and if you’re replacing your water pump and thermostat at 80-100,000 miles, it’s cheap insurance to just replace this before it gives you trouble. 

A failure of your Cayenne’s coolant valley pipe will include coolant collecting inside the valley pan, a noticeable smell of coolant, and a low coolant level. 

 

Upper front coolant pipe/thermostat housing

Similar to the rear coolant crossover pipe, the upper front coolant pipes are bonded into the Cayenne’s thermostat housing. There is an updated 957 thermostat housing from Porsche that has these two pipes secured with bolts rather than glue, so it’s clearly something they’re aware of as far as problems go, but this failure is less common than the rear coolant crossover barb failure. 

Symptoms of a bad upper front coolant pipe failure would be an obvious smell of coolant, visible coolant loss at the top of the engine around the thermostat housing, and a major loss of coolant in the case of total failure. 

 

Water pump/thermostat

Just as on all other Cayenne engines, the 4.8 L V8 water pump will eventually begin to leak and require replacement. We recommend replacing it around 80,000 miles as a preventative maintenance best practice. If the water pump fails completely, it can result in overheating due to lack of coolant flow, or the impeller can make contact with the block and begin to cause some damage. With an aluminum block and head engine such as the M4801/M4851, you will want to avoid any overheating as only a small amount of time overheating can cause head gasket, block, and head issues.  

The thermostat assembly can also fail, causing the thermostat to either stick open or closed. 

Symptoms of a failing water pump include a coolant leak from the top front of the engine block, low coolant levels, and a noticeable smell of coolant. If your water pump fails completely, it may result in overheating as well.  

There are several common signs to indicate your engine thermostat may be failing. If the thermostat sticks closed, the engine will run hot and possibly overheat, even in cooler weather. If it sticks open, it will take too long for the engine to come up to temperature, or it may never come up to temperature. Either of these symptoms will typically result in a check engine light and stored fault codes for a performance malfunction or mechanical malfunction in the cooling system. We recommend replacing both the thermostat and water pump at the same time whenever one is needed.

 

Coolant expansion tank

It’s common for the coolant expansion tank to crack on all engine variants of the Cayenne. 

When your coolant expansion tank fails, it will begin to leak. This will produce a noticeable smell of coolant and an obvious loss of coolant, usually visible near or around the front passenger side of the engine bay or tire. Once the level is low enough, you will have a low coolant warning message on your dash. 

 

High-pressure fuel pump

The Cayenne 957 4.8 L high pressure fuel pump (HPFP) can fail and require replacement. Replacing the HPFP is fairly easy, but does require removing the intake manifold to access it, and it is one of the more expensive components on the 4.8 L Cayenne engines. 

Symptoms of a bad HPFP include extended cranking before starting, a noticeable loss of power, check engine light, and fuel-pressure or fuel-trim related engine codes and error messages. 

 

In-tank fuel pumps

The Porsche 957 Cayenne has a saddle-style fuel tank with low-pressure in-tank fuel pumps on both the left and right sides. It’s typically best to replace these as pairs as once one pump goes bad, the other will often not be too far behind it. When replacing these fuel pumps, it is extremely important to have as low a fuel level as is possible. If the tank is nearly full, you will need to drain it before performing the service. 

Symptoms of bad in-tank fuel pumps include a loss of engine power, stumbling, stalling, being slow to start, or not starting at all.

 

Brake vacuum pump 

The M4801 and M4951 4.8 L Porsche Cayenne V8 engines feature a brake vacuum pump to assist in building vacuum for the power brake system. This failure is usually internal and not noticeable with an outside visual inspection. The pump will leak oil internally, and if it goes unchecked, this can lead to damage in other parts of the brake system and require extensive cleaning or replacement of the various vacuum lines and check valves to remove the oil residue.  

Symptoms of a bad brake vacuum pump include an increase in the required brake pressure to come to a stop and a hard brake pedal.

 

Porsche 957 Cayenne S/GTS/Cayenne Turbo 4.8 L V8 maintenance recommendations 

 


 

Porsche 955 Cayenne 3.2 L NA VR6 (Engine Code: BFD M02.2Y)

06_955 Porsche Cayenne Base 3.2 VR6 engine bay

The base model Porsche 955 Cayenne was introduced one year later than the Cayenne S and Turbo and is the only Porsche Cayenne that shares an engine with another vehicle from the VW/Audi lineup. The M02.2Y 3.2 L narrow-angle VR6 engine is found in a variety of other VAG cars, including the Mk4 and Mk5 Golf R32, Mk1 and Mk2 TT 3.2 Quattro, and Audi A3 3.2 Quattro. While not as powerful or sporty as its V8-powered stablemates. The 3.2 L VR6 features a durable cast-iron block with a narrow-angle 15-degree inline V6 design and a single aluminum head, 4-valves per cylinder, variable valve timing, a dual-plenum intake manifold, and port injection. Unlike the V8 engines, the VR6 features a standard oil pan design, also known as a wet sump. Most major components do carry over between the Porsche VR6 and those used in other VW and Audi models, with the exception of the intake manifold and components. 

Thanks to its proven design, Porsche Cayenne V6 engine problems are fairly rare. Like any other Cayenne engine, you will see the best reliability from the 3.2 L VR6 when it’s properly cared for in terms of regular oil changes with the best quality approved oil. You will also likely see some cooling system issues thanks to composite plastics used throughout the 3.2 L VR6 design. With proper care, it should be no trouble to see 200,000 miles or more from any 3.2 L VR6 engine. 

Technical Specifications:

  • Engine code: M02.2Y
  • Years: 2004-2006
  • Models: Porsche Cayenne Base
  • Engine type: Naturally Aspirated narrow-angle V6, cast-iron block and aluminum head, DOHC, 4-valves per cylinder, Porsche VarioRam dual-plenum intake manifold, variable intake, and exhaust valve timing
  • Displacement: 3.2 L (84mm bore x 95.9mm stroke)
  • Power: 247hp/229lb-ft of torque (Cayenne Base)

 

Porsche 955 Cayenne 3.2 L VR6 Engine Problems

Coolant pipe

This is a common failure point on all VR6 engines dating back to the introduction of the Corrado SLC back in 1992 and is sometimes called the VR6 crack pipe. The plastic coolant pipe that runs between the water pump and thermostat housing will age and eventually crack at one of the barb fittings, causing a major coolant leak. If you replace this coolant pipe preventatively along with the thermostat/thermostat housing when you replace your water pump, it shouldn’t be a problem, as they will usually last a solid 80-100,000 miles without issue. An aftermarket upgraded coolant pipe from 42 Draft Design or Gruvenparts is a nice alternative and certainly is a stronger piece.

The only symptom of Cayenne V6 engine coolant pipe failure is complete and total instantaneous loss of coolant from the middle of the engine block on the driver’s side of the engine. You will notice the smell of coolant, as well as have a low coolant level warning on your 

 

Water pump

Just as it does on the V8 Cayenne engines, the water pump on the Cayenne VR6 engine will fail as the miles pile on. While the iron block and aluminum head design is not as delicate as the aluminum V8s, you still don’t want to ignore this kind of failure. Replace the water pump every 100,000 miles as preventative maintenance along with the coolant pipe and thermostat and thermostat housing assembly. 

The first symptom of a failing water pump is typically a small leak. You will first notice the smell of coolant, and then typically, once it begins to worsen, you will notice a low coolant level in your expansion tank, and you’ll be able to see the coolant leaking down the front of the engine block. 

 

Thermostat/thermostat housing

The 3.2 L Cayenne V6 features a composite plastic thermostat housing and cap, and should be replaced every 100,000 miles, or whenever the other cooling components are serviced. Because of its design, even if it’s not leaking when you remove it to replace the thermostat, chances are it will not seal correctly and will leak after reassembly if you re-use the original housing. This is because it is plastic and can warp over time, and once it's removed, it won't seal. 

Just as on the V8 engines, the 3.2 L thermostat assembly can also fail, causing the thermostat to either stick open or closed.

Symptoms of a bad thermostat include either overheating due to a thermostat that is stuck closed, or an engine that is slow to warm up or never reaches operating temperature due to a thermostat that is stuck open. In either situation, you will likely get an engine fault code for a performance malfunction or mechanical failure in the cooling system, along with a check engine light.

A bad thermostat housing will typically begin as a small coolant leak on the backside of the engine block, near the firewall. If it is not replaced, it will eventually fail completely, resulting in a complete and total loss of engine coolant. 

 

Timing chains

On the 3.2 L VR6, timing chain issues are usually only seen on very high mileage (180,000 or more) or poorly maintained engines. Lack of oil changes causes increased wear on the guides and tensioners. While the parts are not too expensive, you do need to remove the transmission to perform a timing chain service on a VR6 engine. You should replace both upper and lower chains, guides, rails, and tensioners as part of the complete Cayenne V6 timing chain kit

The first indications of needing a timing chain service are an audible chain noise on cold starts and when the engine is transitioning between idle and higher RPMs. Extremely worn timing chain guides and rails will cause timing correlation codes, and the engine can eventually jump time and cause major internal damage. 

 

Intake manifold plenum bushings

This is a carry-over issue seen in other VR6 engines that feature a dual-plenum intake manifold design. The plenum flap has plastic bushings that will wear and allow the flap to move and vibrate. Since the intake manifold is Cayenne-specific, you have to use the Genuine Porsche Cayenne V6 intake manifold repair kit to replace the worn bushings. 

One symptom of worn intake manifold plenum bushings is a very loud rattle, usually at lower RPM, that will go away as the engine crosses into higher RPM. This is generally very noticeable and can easily be confused with a more serious problem such as rod knock or piston slap. 

 

Valve cover gasket

Over time the valve cover gasket will get brittle and hard and will begin to leak. Exact mileage varies, but it’s best to start checking for seepage around 60,000 and continue to check at oil changes after that interval.

Symptoms of a bad valve cover gasket include oil leaking around the valve cover down onto the cylinder head, a noticeable smell of oil, as well as oil down in the spark plug holes that are seen when changing plugs and coils. 

 

Ignition coils 

While generally more durable than some modern engine ignition coils, the 3.2 Porsche Cayenne V6 ignition coils do occasionally fail on the VR6 engines. Preventative replacement at 80,000 miles will help ensure you don’t get stranded, and as with all the other engines we’ve talked about, it’s best to replace them as a complete set. Replacement is easy, and carrying a few spares will ensure you’re never stranded from a random ignition coil failure. 

Just like the other engines we’ve talked about here, a bad ignition coil will result in a rough idle, loss of power, and most likely a flashing check engine light along with fault codes for random/multiple and specific cylinder misfires. 

 

In-tank fuel pumps

The Porsche 955 Cayenne has a saddle-style fuel tank with low-pressure in-tank fuel pumps on both the left and right sides. It’s typically best to replace these as pairs as once one pump goes bad, the other will often not be too far behind it. When replacing these fuel pumps, it is extremely important to have as low a fuel level as is possible. If the tank is nearly full, you will need to drain it before performing the service. 

Symptoms of bad in-tank fuel pumps include a loss of engine power, stumbling, stalling, being slow to start, or not starting at all.

 

Porsche 955 Cayenne Base 3.2 L VR6 Maintenance Recommendations 

 


 

Porsche 957 Cayenne 3.6 L NA VR6 (Engine Code: M5501)

07_Porsche 957 Cayenne 3.6 VR6 base engine bay

The 957 Porsche Cayenne base model carried on using the VW-group VR6 engine for the 957 variant, now featuring direct injection, a more-narrow 10.6-degree V, and a bump in displacement to 3.6 L. Just as in the 955, the 3.6 L VR6 is also used on the same generation VW Touareg, Audi Q7, as well as B6 VW Passat and CC. The increase in horsepower and torque is exactly what the base model Cayenne needed, making the 957 Cayenne base in either Tiptronic or manual trim a great buy. 

The 3.6 L VR6 has proven to be just as reliable as the earlier 3.2 L examples, able to go many thousands of miles with just basic preventative maintenance. Like the 3.2 L, timing chains should not be an issue unless the car has seen extended oil use or been neglected in terms of basic service. Early 2006 and 2007 VW 3.6 L VR6 engines in the Passat were known to suffer from the oil pump drive sprocket nut loosening and causing major engine damage, but this does not seem to affect any of the 957 Cayennes, which were introduced after the VW fix. With care, the 3.6 L VR6 should easily last to 200,000 miles or more before any major services. 

Technical Specifications:

  • Engine code: M5501
  • Years: 2008-2010
  • Models: Porsche Cayenne Base
  • Engine type: Naturally aspirated narrow-angle V6, cast-iron block and aluminum head, DOHC, 4-valves per cylinder, FSI direct fuel injection, Porsche VarioRam dual-plenum intake manifold, variable intake, and exhaust valve timing
  • Displacement: 3.6 L (89mm bore x 96.4mm stroke)
  • Power: 286hp/284lb-ft of torque (Cayenne Base)

 

Porsche 957 Cayenne 3.6 L VR6 Engine Problems

Intake valve cleaning

The 3.6 L VR6 features FSI direct fuel injection and can suffer from carbon build up on the intake valves, similar to most other direct-injected engines. The 3.6 has huge intake ports, so it is unlikely to suffer major running issues, but it will slowly lose performance. How you drive has a huge influence on how much carbon builds up and the type, either sticky and tar-like or something more like charcoal. Lots of short trips, low RPM use, and not using full throttle or running to redline every so often will make the carbon build up more quickly. Cleaning the intake valves is a fairly involved but not technically difficult process. Using a walnut blaster combined with manual cleaning and using LIQUI MOLY Valve Clean as a soaking agent to soften up the carbon is the best way to clean the intake valves. 

Common symptoms of needing an intake valve cleaning include engine misfires at cold start, a rough idle, a loss of power or miles per gallon, and a check engine light related to engine misfires. 

 

Timing chains

The Cayenne 3.6 V6 features a relatively simple and reliable timing chain system that should last well over 100,000 miles, provided that the car receives proper oil changes. We recommend 5,000-mile intervals, as the factory-specified extended drain intervals typically will result in increased wear that leads to worn guides, rails, and tensioners. Because the HPFP is driven off of the timing chain on the 3.6 L VR6, timing chain issues can sometimes manifest as fuel pressure issues and codes due to an out-of-sync pump. The transmission has to be removed to perform a timing chain service on the 3.6 L VR6, so it is a more extensive job. It’s best to replace both the upper and lower timing chains, guides, rails, tensioners, and related components when servicing the timing chains. 

The most common symptoms of needing a timing chain service include chain rattle and noise on cold starts, audible chain noise at idle, and when transitioning from idle to a higher RPM. Fault codes for timing correlation and a check engine light are possible on severely worn timing chains, as is jumped timing and internal engine damage. A rare but possible side effect includes fuel codes and issues related to the HPFP. 

 

Water pump

Similar to the 3.2 L VR6 engine, the 3.6 L Cayenne VR6 will usually need the water pump replaced once it begins to leak due to worn bearings and damaged seals. These engines seem to go quite a long time before needing the water pump replaced, but it’s still something to be aware of and consider replacing as preventative maintenance. 

If your water pump fails, you will have a coolant leak that shows up on the front, forward side of the engine block. Once the leak becomes more substantial, you will have low coolant warnings, a low level in your coolant expansion tank. If it fails completely, the engine can overheat, and you can damage the engine. 

 

Thermostat/thermostat housing

The 3.6 L VR6 has a completely new and improved coolant pipe system and thermostat housing design. Because of this, it is not as failure-prone as the 3.2 L and earlier VR6 coolant pipe designs, but since everything is still made of composite plastic, it is still a potential problem to have a Cayenne 3.6 coolant leak. Because of the design, you should replace both the thermostat, thermostat housing, and all related plastic components at the same time. 

If your thermostat is beginning to fail, there are a few common symptoms. If it is sticking closed, the engine will overheat or have a higher than normal engine temperature, even when driving at speed and in cooler weather. If the thermostat sticks open, the engine will be slow to warm up or may not come up to temperature at all. Both of these will usually result in a check engine light for cooling system performance or a mechanical malfunction.

If your coolant thermostat housing is beginning to fail, it will usually leak at the gasket at the cylinder head or another junction. If it fails completely, you will have instant and total coolant loss. As with any engine, if you continue to drive it while it’s overheating or doesn’t have coolant, you can severely damage the engine. 

 

Air/oil separator

The air/oil separator, better known as the PCV valve to most VW owners, is known to fail on the 3.6 L VR6, creating rough running at idle. The ECU will often adapt to the incorrect flow but letting a bad PCV go without repairing it will usually create other issues. The most common is the rear main seal leaking or being damaged due to an increase in crankcase pressure. The PCV valve is built into the valve cover so it can only be repaired by either replacing the complete valve cover or using an aftermarket fix-kit that includes a new rubber diaphragm.

If the PCV valve is going bad on your 3.6 L VR6, the common symptoms will include a rough idle, check engine light, stored fault codes for lean run condition, and a whistling noise at idle. 

 

Valve cover gasket

The 3.6 L VR6 can suffer from a leaking valve cover gasket, typically at higher miles. As the gasket gets hard and brittle, it will crack and begin to let oil seep out. These usually start as a slow leak and get worse over time. 

If your Cayenne V6 valve cover gasket is leaking, you will have a visible oil leak from around the valve cover and cylinder head. If the spark plug hole gasket sections fail, you will see oil on the bottom of the ignition coils and on the porcelain of the spark plugs.

 

Ignition coils

While generally more durable than most individual ignition coil-per-cylinder designs, these do occasionally fail on the 3.6 L VR6 engines. Preventative replacement at 80,000 miles will help ensure you don’t get stranded, and as always, you should never drive if your Cayenne has a flashing check engine light. As always, it’s best to replace all ignition coils at the same time to ensure the best performance and reliability. 

Symptoms of a bad Cayenne 3.6 V6 ignition coil include engine misfires on one or more cylinders, causing a rough idle, loss of power, and a check engine light. A flashing check engine light lets you know the misfire is still happening, and you should immediately stop driving the vehicle. You will usually have codes for random/multiple misfires and a specific code for each cylinder that has a bad coil pack. 

 

In-tank fuel pumps

The Porsche 957 Cayenne has a saddle-style fuel tank with low-pressure in-tank fuel pumps on both the left and right sides. It’s typically best to replace these as pairs as once one pump goes bad, the other will often not be too far behind it. When replacing these fuel pumps, it is extremely important to have as low a fuel level as is possible. If the tank is nearly full, you will need to drain it before performing the service. 

Symptoms of bad in-tank fuel pumps include a loss of engine power, stumbling, stalling, being slow to start, or not starting at all.

 

957 Porsche Cayenne Base 3.6 L VR6 Maintenance Recommendations 

08_Porsche 957 Cayenne and Cayenne S

With the proper care and service, any 955 or 957 Porsche Cayenne should see many many thousands of miles of reliable performance. Being a high-performance SUV, the Cayenne has some additional considerations for preventative maintenance and general service. The reward is in the unmatched driving experience that the Cayenne can deliver, whether on or off road, and at nearly any speed. 

If you have any questions about the Porsche 955/957 engine options, problems, or maintenance, leave them in the comments section below. 

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Written by :
Nathan Brown

FCP Euro's Event Director by day, writer and contributor by night, and wanna-be race car driver on the weekends. Nathan has been working in the VW and Audi performance aftermarket for nearly two decades, and dabbled with Porsche and BMW. He also used to write under the pen-name of Alex Rogan for magazines like Eurotuner, Performance VW, Total 911, and European Car. He has a Cornflower Blue Rabbit Edition GTI daily driver which is surprisingly still mostly stock, and a Mk5 GTI track car which is mostly not. ••• Instagram: @njbrown55


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