Is your MK7 Volkswagen GTI constantly low on coolant or are you experiencing intermittent overheating? If you are, there's a good chance that your water pump and thermostat housing assembly are to blame. Addressing the issue at the first signs of failure can save you a lot of headaches and money down the line.
Aaron Davis walks us through the entire process of replacing your water pump and thermostat housing assembly step by step in the video and guide, below.
Volkswagen/Porsche models and years applicable:This water pump and thermostat assembly fits a range of MK7 Volkswagens and Porsches, including:
What are the symptoms of a bad water pump and thermostat housing?
- Coolant leaking through the weep hole
- Water pump pulley shaft play which indicates a bad bearing
- Squeaking from the water pump at idle
- Low coolant light on the instrument cluster
- Intermittent or constant overheating
Ignoring the signs of a failing water pump and thermostat housing can be extremely detrimental. There's the possibility to cause irreparable engine damage due to overheating.
Volkswagen doesn't have a regular service interval on the water pump and thermostat. However, you can expect to have to replace it as early as 25,000 miles. For the most part though, water pumps and thermostat housings start to need replacing around the 50,000 mile mark.
How long will it take to replace my water pump and thermostat housing?
Book time to complete the job is 5 hours. If you're doing the job yourself for the first time, you can expect it to take you between 6 hours and a full day.
How much does it cost to replace my water pump and thermostat housing?
If you plan to take your car to the dealer to have this job done, you'd be looking at it costing north of $1200. By purchasing the parts through us and doing this job yourself, you will only pay a fraction of the cost. Plus, when you need to replace them again, you can make use of our Lifetime Replacement Guarantee.
Tools required to replace your MK7 Volkswagen GTI water pump:
- Ratchet set
- Torque wrench
- Metric socket set
- Torx socket set
- Metric wrench set
- Hook pick set
- Flat band hose clamp pliers
- Plier set
- Torque wrench
- Audi/VW Fuel Injector Puller/Remover
Parts required to replace MK7 Volkswagen GTI water pump:
Steps required to replace MK7 Volkswagen GTI water pump:
Step 1: Remove the coolant expansion tank cap
Start by removing the engine cover and the air intake. On this car, there's an aftermarket intake installed. However, removal of the stock airbox is very straightforward.
You will need a flat head screwdriver to remove the hose clamps and possibly a pick tool to help remove the electrical connector.
Step 2: Remove Engine Covers and Air Intake
Start by popping off any plastic engine covers that impede your access to the engine itself. These should simply snap right off without any hassle.
Next, you will want to remove the air intake system. On the car shown, this is an aftermarket intake, but the steps remain the same for the most part.
Using a 7mm socket, first remove the hose clamp off of the intake.
Aaron's intake has an extra bolt as well as a secondary air filter that you will not have if you have the stock air intake system.
Step 3: Remove the Intake Duct
The intake cooling duct sits at the front of the car. This is held in place by 2 T20 fasteners and 2 T25 fasteners. Start by removing the T20s, once you do that, you can remove the cover and gain access to the T25s. After that, there is a coolant line to remove.
Step 4: Loosen and Remove the Fuel Lines from the High-Pressure Fuel Pump
This step, you're going to want to release the pressure from the high pressure fuel pump (HPFP). To do so, slowly loosen the 17mm that connects high-pressure fuel line to it. For this step, make sure to wear safety glasses as you do not want pressurized fuel in your eyes. A rag also helps to stop any fuel from going anywhere.
Using pliers, pull the clamp on the fuel hose back so that the hose can be removed from the HPFP.
Step 5: Remove the Belly Pan
Now it's time to get under the car to remove the plastic belly pan. We have a lift to better demonstrate how to do this, but you can do this on jack stands just as easily.
There are 7 T25 fasteners that hold the belly pan in place. Once you remove those, you can use a flat head screwdriver to pop the two last clips that will be holding it in place.
Step 6: Remove the Coolant Pipe
Back on the topside of the engine, it's time to remove the coolant pipe. This is held in place by 2 T30 fasteners and a hose clamp.
Now, below the throttle body, you will want to use a hose pick to free up the radiator hose. Once you loosen that, you will be able to use the flat band hose clamp pliers to loosen the clamp. Spraying a small amount of lubricant on the hose can help slide the clamp down the hose itself. Coolant will come out of these lines, so you might want to have a catch pan underneath the car and some rags handy.
The plastic lines that these coolant hoses are connected to are plastic and can be broken if you apply too much force. Because of this, use care when remove these hoses.
Step 7: Disconnect the Throttle Body Hoses and Connectors
The hose connected to the throttle body is held on by a hose clamp just underneath the throttle body itself. Remove this using a 7mm socket.
Switching back to underneath the car, you're going to want your hose picks handy. Under hear, start by freeing up the wiring harness. This will un-clip using a pick tool.
Using your hook pick again, you need to free up the large coolant hose. With the pick, the clamp that holds it in place will release easily.
After the coolant hose is release, you need to remove the MAP sensor as well. This is located behind the coolant hose, so again, using the hook pick, is the easiest method in doing so.
Still underneath the car, you need to remove the 2 T30 fasteners that hold the throttle body pipe in place. You will find one of the T30s located behind the MAP sensor. It can be a little tricky to get to because it is hard to see.
The next thing to remove underneath the car is the coolant hose. To do so, you must remove the hose clamp that holds it in place using a 7mm socket. A radiator hose pick will help you remove the hose once again.
The last step in this process is to finally remove the entire hose assembly. Everything should be free at this point, you just have to wiggle and fight it out of place slightly.
Step 8: Remove the Intake Manifold Bracket
The intake manifold bracket is held in place by 2 13mm hex up top, and a single M10 triple-square below. Once you remove these, you will want to use a flat head screwdriver to remove the wiring harness.
Step 9: Remove the Throttle Body
It's finally time to remove the throttle body itself. It is held in place by 4 aluminum T30s. Since these are aluminum, make sure that your socket is seated entirely. You don't want to strip any of these out.
As these are behind/underneath the throttle body, Aaron shows us a helpful tip in the video on how to use a flashlight and a mirror to locate these fasteners.
You will want to hold the throttle body when removing the last T30 as it has a tendency to fall once the last fastener is removed.
Step 10: Remove Wiring Harnesses from Intake Manifold
There are many various clips and connectors that connect to the intake manifold itself. You will need to remove all of these to remove the manifold. It is helpful to use a hook pick to depress the clips when removing these.
Any clips with the grey connectors as displayed below have to be operated a bit differently. These are safety clips and can't be removed without first sliding the grey part back.
Since it is tough to explain exactly where all of these clips and connectors are exactly, it is helpful to reference the video at the top of the page.
Step 11: Remove Bracket from Intake Manifold
Below all of the wiring you just removed, there's a bracket that must be removed from the manifold. This bracket is held in place by 2 T30s.
There is one last connector attached to this bracket that you will want to remove once it is detached from the manifold. It is easiest to remove this with a hook pick.
Step 12: Remove the Oil Filter Housing
Another thing that has to come off to remove the intake manifold is the oil filter housing. You will need a 32mm socket designed specifically for the oil filter cap.
Step 13: Disconnect Sensors from Intake Manifold
There are two more sensors on the manifold that will need to me removed. One of these is another safety clip with the grey part that must be pulled back when disconnecting.
Step 14: Remove the Intake Manifold Fasteners
You have finally removed everything that needs to come off to access the manifold screws. There are 2 10mm screws and 8 T30 screws that need to come out.
When removing these screws, we recommend using a magnetic pickup tool to prevent dropping them into the bowels of the engine.
Step 15: Remove the High-Pressure Fuel Pump (HPFP)
There is a T30 that holds the HPFP to the intake manifold. To access that T30, first you have remove an additional T30 on a bracket directly in front of it.
This T30 on the bracket is captive, so you don't have to worry about it falling from its position.
Step 16: Remove the Intake Manifold
You can finally remove the intake manifold from the cylinder head. At this point, you might need to disconnect the high-pressure fuel line at the fuel rail to be able to completely remove the manifold. You can pull up and away from the car and the manifold should come right off.
Once you have the manifold off, you need to flip it over and disconnect the vacuum line assembly from underneath. I would recommend referencing the video if you have trouble removing these lines.
Step 17: Remove the Coolant Lines
To remove the coolant lines, you want to use a hook pick to pull the clips outward. Once the clips are released, you can wiggle and pull on the coolant lines to remove them. You will need to do this for both the upper and lower coolant lines.
We recommend placing a catch pan underneath where you are working as there will be coolant inside the lines.
Step 18: Remove the Belt Cover Housing and Remove the Belt
First, start by unclipping the wiring harness from the housing cover. Once that is unclipped, you can remove the 2 T30 screws that hold the housing in place. We recommend using a stubby T30 as the available space is tight.
With the cover off, you can remove the belt that is driven by the balance shaft.
Step 19: Remove the Water Pump and Thermostat Assembly
It's finally time to remove the water pump and thermostat as all one assembly. It is held in place by 5 T30s. These are captive, so you don't have to worry about them falling inside your engine bay. The lower screws are tough to get at, so it helps to have a small mirror and a light to locate them.
With those removed, you can wiggle and pull on the water pump until it comes free. There will be a single connector attached underneath that needs to be removed. It's helpful to use a tool pick to work the safety tab free.
Step 20: Install the New Thermostat Housing on the Water Pump
The water pump and thermostat housing ship as two pieces, so you will need to install the new thermostat housing on the water pump. To do so, simply line up the dowels and drop it in place. They are fastened together by 5 T30 bolts.
Before the next step, be sure that the thermostat gasket isn't still attached to the engine block.
Step 21: Reverse Steps 19-3 Above and Reinstall
The reinstallation process is nearly a perfect reversal of the steps above. One issue you might run into is placing the belt back on the balance shaft. To do this, Aaron recommends turning the engine over by hand using a long ratchet and 24mm socket while slowly walking the belt on.
If you get hung up, I recommend referencing the video above as Aaron walks you through the entire process.
Step 22: Refill the Cooling System
The last important step of this job is to refill your cooling system. Usually it's a pain to bleed the air out of your cooling system. However, Aaron uses the new Uview Airlift II Cooling System Filler Kit. This is a vacuum filling system that removes all of the air in your system before filling it with coolant.
To use this vacuum filler, you attach it to your coolant reservoir, hook up shop air and watch the gauge move as it pulls vacuum. Once vacuum is achieved, you open the valve to the coolant line which you have submerged in your bucket of coolant. It will immediately start filling your system. Once the gauge reads "0", you know it's completely filled.
MK7 Volkswagen Water Pump & Thermostat Housing Torque Specs:
- Thermostat housing T30s - 8Nm
- Intake manifold T30 and 10mms - 9Nm
- Intake manifold bracket 13mm - 10Nm
- Intake manifold bracket M10 triple square - 20Nm
- Throttle body T30s - 7Nm
- 32mm oil filter cap - 2.5Nm
The job was fairly involved, but there's nothing to really get caught up on like with other DIYs. You should be good as new with a fully functioning water pump and thermostat.
Writer/Editor at FCP Euro and owner of a daily R53 MINI Cooper, a track-built R53 MINI, and a 1997 Dakar Yellow E36 M3 Sedan. ••• Instagram: @evan.madore