Replacing the oil filter housing gaskets is a common repair for BMW N52, 54, and 55 motors.
One important thing to realize about the oil filter housing is that it contains passageways for both oil AND coolant. So after you replace the gaskets, you need to bleed the water pump, which is electric.
With help from members of our Innovation Council, we’ve compared procedures from a variety of sources, and feel the seven-step process outlined in this episode of Inside the Brands, is the smartest, safest way.
An important preparatory step is to first connect a battery charger to your car. This is critical because you are going to have leave your car’s ignition on for over 10 minutes without running the engine.
Also, if you have a smartphone or other way of setting a countdown timer, you’ll want to have that handy.
Turn on the car’s ignition — but do not start car. The engine should not be running for the first part of the process.
Turn the vehicle’s climate controls to the warmest setting possible, and the fan to the lowest setting.
Push the accelerator to the floor for 10 seconds. You should hear the water pump cycle on.
This is where you’ll need the timer mentioned above.
Set your timer for 12 minutes and let the water pump cycle for that entire time. While it’s doing that, get out of the car and check for leaks. If you find leaks, take appropriate measures and start the process over from the beginning — you’ll need to turn the ignition off for 5 minutes to reset things before you do that.
After the 12 minutes are over and assuming there are no leaks, turn the car off and check the coolant reservoir. It should be slightly lower.
At this point, you can turn the car on again, this time starting the engine.
As the car idles, monitor the temperature gauge. As before, check for leaks. If you find any, or if the temp starts to climb faster or higher than expected or if the temp does not hold, shut the car off and repeat the entire process. Remember to turn off ignition for 5 minutes between procedures.
If everything is functioning properly, you can consider the job complete and replace the splash guard.
If you’re looking for OE-quality replacement gaskets for the oil filter housing repair — CRP Automotive carries the correct AJUSA units (CRP part #01099100 & #01263000).