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You might already be experiencing the symptoms of a failed valve cover or PCV system on your BMW N55 engine without even noticing it. Leaks, burning oil, and dirty oil are all signs that your valve cover could be to blame. This valve cover from BMW comes with everything you need to replace the whole system in your garage in half a day or less. 

In this guide, Gareth Foley, our BMW Catalog Manager, tears into an N55 and and teaches us a few of his tips and tricks when replacing the valve cover. 

 

BMW models and years with the N55 engine:

There is a wide range of models and years that shipped with the N55 engine. This DIY will apply to all of them.

  • 2008-2017 BMW X6
  • 2011-2017 BMW 535i GT
  • 2010-2012 BMW 550i GT
  • 2011-2017 BMW X3
  • 2009-2012 BMW 750i
  • 2012 BMW 650i
  • 2009-2012 BMW 750Li
  • 2012-2018 BMW 640i
  • 2010-2012 BMW 750i xDrive
  • 2012 BMW 650i xDrive
  • 2010-2012 BMW 750Li xDrive
  • 2013-2018 BMW 640i Gran Coupe
  • 2010-2012 BMW 550i GT
  • 2013-2015 BMW X1
  • 2010-2017 BMW X5
  • 2013 BMW 135is
  • 2013-2015 BMW 740Li
  • 2013-2015 BMW 740i
  • 2011-2015 BMW 335i
  • 2012-2016 BMW ActiveHybrid 5
  • 2011-2015 BMW 335i xDrive
  • 2013-2015 BMW ActiveHybrid 3
  • 2011-2016 BMW 535i
  • 2013-2015 BMW ActiveHybrid 7
  • 2015-2018 BMW 640i xDrive
  • 2011-2013 BMW 550i
  • 2014-2018 BMW 640i xDrive Gran Coupe
  • 2011-2017 BMW 535i GT
  • 2014-2016 BMW 435i
  • 2011-2012 BMW Alpina B7
  • 2014-2016 BMW 435i xDrive
  • 2011-2012 BMW Alpina B7L
  • 2014-2016 BMW 335i GT xDrive
  • 2011-2013 BMW 135i
  • 2014-2016 BMW M235i
  • 2011-2012 BMW Alpina B7 xDrive
  • 2015-2016 BMW 435i Gran Coupe
  • 2011-2012 BMW Alpina B7L xDrive
  • 2015-2016 BMW 435i xDrive Gran Coupe
  • 2011-2016 BMW 535i xDrive
  • 2015-2016 BMW M235i xDrive
  • 2015-2018 BMW X4
  • 2011-2013 BMW 550i xDrive
  • 2016-2018 BMW M2

 

What are the symptoms of a bad valve cover gasket?

    • Oil leaks
    • Burning oil smell
    • Overly dirty oil
    • Cracks in the valve cover

I wouldn't ignore the signs of a faulty valve cover. If you suspect that it is the issue, I'd inspect it to see if it's just the valve cover gasket, or if you have a crack in the cover itself. 

BMW doesn't have a regular service interval for the valve cover, but many people start to see symptoms around the 70,000 mile mark. However, it's possible for the gasket to fail earlier or develop a crack in the cover. 

 

How long will it take to replace my BMW N55 valve cover?

Doing the job yourself, you can expect it to take around 6 hours give or take depending on how comfortable you are in the engine bay. 

 

How much does it cost to replace my BMW N55 valve cover?

If you plan to take your car to the dealer to have this job done, you can expect this to run anywhere from $1500 to upward of $2000. 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 BMW N55 valve cover:

 

Parts required to replace BMW N55 valve cover:

 

Steps required to replace BMW N55 valve cover:

Step 1: Remove the engine cover and intake

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. 

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Step 2: Remove the inlet pipe

To remove the inlet pipe, you have to remove the connectors from it. Low and to the front, there's an electrical connector. Further back from that, you have one corrugated pipe as well as one vacuum line. The last thing to remove is the hose clamp that is lowest and in toward the front. 

Use care when removing all of these clips. Some of the pipes and the clips themselves become brittle over time and can break very easily. 

There's only one fastener holding on the inlet pipe, and it's a 10mm. Once that's removed, you can simply pop the entire inlet pipe right off. The inlet pipe can become brittle over time, so be cautious not to crack/break it when removing it. 

We suggest threading the 10mm fastener into the new valve cover so that you don't lose it. 

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05--bmw-n55-spark-plug-replacement-vacuum-pipe-connector

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09-bmw-n55-spark-plug-replacement-inlet-pipe-removed

 

Step 3: Disconnect the battery

Since you have to disconnect the battery leads inside the engine bay, you should always disconnect the battery in the trunk before doing so. Do so before going forward. 

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Step 4: Remove the crossover brace

Using a 16mm socket, remove the two bolts that hold the crossover brace in place. 

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Step 5: Remove wiring harness from clips

The wiring harness is held in by multiple clips along the back side of the engine. It has to be removed to make room to get to all of the bolts. 

05-bmw-n55-valve-cover-wiring-harness-clips

 

Step 6: Disconnect all electrical connectors

There are a number of electrical connectors that have to be removed to get to the rest of the valve cover. These are the wastegate actuator connector, O2 sensor connectors, the valvetronic unit connector, and two cable holders. Some of these it helps to gently use a screwdriver or pliers. 

06-bmw-n55-valve-cover-electrical-connectors

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Step 7: Remove the vacuum lines

Remove the vacuum line from the valve cover. There will be a vacuum plug in one of the two holes, make sure to transfer the plug to the corresponding inlet on the new valve cover. Vacuum lines can sometimes be stubborn, so use care and work them off slowly. 

The second vacuum line that needs to be replace goes to the vacuum accumulator. This line has a squeeze-tab type connector. Be careful when using pliers on this as you do not want to break it. 

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08-bmw-n55-valve-cover-vacuum-line-actuator

 

Step 8: Remove the ignition coils

Now you have access to the ignition coils. The first step is to remove the connectors. All you have to do is flip up the connector, and it should pull itself right out.

Next, you need to remove the ground to the ignition coils using an 8mm socket. Be careful not to drop one of these screws into your engine bay.  

Once that's done, you can pull the ignition coil straight out. It's helpful to use a tool, such as a pick or a screwdriver, through the hole on the top of the coil to have a little more to grab onto. 

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11-bmw-n55-spark-plug-replacement-remove-ignition-coils

 

Step 9: Disconnect miscellaneous brackets

Using a T30 socket, remove the bracket from the back of the engine. 

11-bmw-n55-valve-cover-bracket-t30

 

Step 10: Disconnect the high-pressure fuel lines

Using a 14mm wrench, you can remove the flare nuts on the high-pressure fuel lines. Since the system is pressurized, it's helpful to place a rag over the fitting when loosening it. It also helps to wear safety glasses in this case as well. Do this for all of the fittings on both sides of the fuel rail. 

Gareth lets us onto a little tip to save you a lot of potential headaches. Since you will still be working in the engine bay, he cuts the finger tips off of rubber gloves to use as caps over the high-pressure fuel connections. This keeps debris out of the rails, preventing clogs in the future. 

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Step 11: Remove the valvetronic motor seal

Remove the two E6 bolts that hold the valvetronic motor seal in place. The motor itself doesn't need to be removed, just these two bolts. These bolts are self-tapping and will be replaced with new ones. The seal itself is one-time-use as well, and is included in the kit. 

 

Step 12: Remove the valve cover bolts and remove the valve cover

There are 24 E12 bolts that hold the valve cover in place. A few of them toward the back of the engine are tough to get to, you will probably need to shift the cowl out of the way. 

Once these are loosened, you can remove them fully using an electric ratchet to make your life easier. 

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Step 13: Install new valve cover

When installing the new valve cover, you want to be careful to not pinch, roll, or let the gasket fall off the new cover. If you're lucky as Gareth was, you can install it in one shot. 

Once the valve cover is in place, you want to start putting the new screws in place. Tighten them just snug by hand first, you will follow this up by torquing them to spec. 

When torquing the valve cover bolts, you want to alternate the pattern across and from side to side. The goal here is to evenly compress the gasket. As these are aluminum bolts in a plastic valve cover, you want to be gentle with these. The torque spec is 8.5Nm or 6lb-ft. 

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Step 14: Follow 12 through 1 in reverse to reassemble

The rest of the process is fairly straight forward. You simply want to reverse the steps above until everything is put back together. If you get stuck on the process, in the video at the top, Gareth shows the entire process of reinstallation.

 

BMW N55 Valve Cover Replacement Torque Specs:

  • All 24 valve cover bolts: 8.5Nm / 6 lb-ft
  • Small fuel lines: 23Nm / 17 lb-ft
  • Large fuel line: 30Nm / 22 lb-ft
  • Fuel rail mounting bolts: 13Nm / 10 lb-ft
  • Strut bar center: 100Nm / 74 lb-ft
  • Strut bar to shock tower: 34Nm / 25 lb-ft
  • Intake manifold nuts and bolts: 15Nm / 11 lb-ft

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 valve cover and PCV system. 

If you're interested in more DIYs for your BMW, you can visit bmw.fcpeuro.com or subscribe to our YouTube channel. 

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Written by :
Evan Madore

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


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