This article gives detailed instructions on replacing the oil filter housing gasket and oil cooler gasket in a BMW N52 six cylinder engine. Even though we used a 2006 530xi (E61) to perform this repair, this article can be applied to any other BMW vehicle with the N52 six cylinder engine, including the 1,3,5,6,7,X1,X3,X5 and Z4 models with minor modifications to the repair steps.
A BMW N52 oil filter housing gasket replacement will cure the infamous oil leak dripping from the left side of the engine.
The BMW N52 engine has several well known oil leak issues – most notably the oil filter housing and oil cooler gaskets. Located on the front left side of the motor, the housing gasket seals the oil filter assembly to the cylinder head preventing engine oil from leaking from the connection seam. Since the BMW N52 oil filter housing also serves as the mounting platform for the oil cooler, there is a second gasket on the front of the housing that is prone to leaking as well.
Like all rubber parts in the N52 engine, long term exposure to the motor’s brutal heat conditions causes the housing and oil cooler gaskets to become brittle and eventually fail. Classic symptoms of a leaking BMW N52 oil filter housing gasket are: engine oil “puddling” on the top and/or sides of the housing, oil or coolant on the cylinder head or ground around the front of engine and smoke emanating from the engine compartment.
A BMW N52 oil filter housing gasket replacement is not technically challenging and can be done by any home mechanic with average abilities. We strongly recommend replacing both the housing and oil cooler gaskets during this repair…if one of them is leaking, the other is most likely going to fail soon as well.
1. Oil filter housing gasket (required) – The BMW N52 oil filter housing gasket is inexpensive, so it only makes sense going with a high quality OEM replacement. We give you several choices based on your budget and brand preference.
2. Oil cooler gasket (required) – As discussed above, you should always replace your oil cooler gasket with the housing gasket (and vice versa).
3. Engine coolant (required) – Since the N52 oil filter housing also serves as an oil cooler, you will lose a little bit of coolant during this repair. Only refill your BMWs coolant system with Genuine BMW coolant mixed 50/50 with distilled water.
4. Oil filter (optional) – Since the oil filter housing will have to be removed to complete this repair, now is an excellent time to replace your oil filter. Keep your BMWs oil clean with a fresh oil filter.
As discussed above, replacing the oil filter housing and cooler gaskets on the BMW N52 six cylinder engine is very straightforward with very few parts that need to be removed or cleared out of the way. There is one oil filter housing mounting bolt located under the intake manifold, but it can be removed with a socket extension and universal joint. You DO NOT need to remove the intake manifold on the N52 engine to reach this mounting bolt.
- Locate the oil filter housing and oil cooler on the front left side of the engine.
- Remove the protective plastic cover off of the oil cooler. It simply unsnaps.
- Use an oil filter wrench to remove the cover from the oil filter.
- Remove the oil filter from the housing. Allow the engine oil to drain out of the housing. We like to use our fluid vacuum pump to suck all of the old oil out to avoid a mess when the housing is removed.
- Disconnect the oil pressure sensor from the housing by depressing its metal release clip and pulling it free.
- The oil cooler has a coolant hose attached to it that will need to be removed. We like using a pair of plastic pinch off pliers (like the one shown below) to clamp off the hose prior to removal. It is not absolutely necessary to use one, but it does help prevent an excessive flow of coolant from spilling out.
- Loosen the hose clamp and remove the coolant hose from the oil cooler. You may need to use the assistance of a flat blade screwdriver to get it off (be careful not to puncture it). Have a rag ready…a small amount of coolant will drain out of the oil cooler.
- Prop the coolant hose up and out of the work area so it doesn’t leak coolant.
- Next, the cylinder head coolant hose must be removed. This hose must be removed to access the lower oil filter housing bolt. Start by disconnecting the cylinder head coolant temperature sensor by depressing its metal release and unplugging it.
- Use a 10mm socket wrench to remove the two bolts anchoring the thermostat coolant hose to the cylinder head.
- Grasp the thermostat coolant hose and remove it from the cylinder head. You may have to rock it back and forth while pulling to get it to release. Have some rags ready to catch the small amount of coolant that will drip from the cylinder head.
- Stuff a lint free rag into the cylinder head to keep the coolant loss to a minimum until the repair is finished.
- You now have clear access to the lower oil filter housing mounting bolt. Use an E10 external torx bit to remove it.
- Remove the upper mounting bolt with the E10 socket.
- The final mounting bolt is underneath the intake manifold. Use a socket extension and a universal swivel to remove it.
- Grasp the oil filter housing and pull it free from the cylinder head. There is no need to disconnect the upper radiator hose from the oil filter housing for this repair (we feel the less hoses disconnected the better).
- Use a metal pick to remove the old oil filter mount gasket.
- Use CRC Brakleen to thoroughly clean the oil filter mount and cylinder head. Now is a great time to clean the engine block of any old oil sludge and dirt. Pay careful attention to the cylinder head – scrub it with a lint free cloth and CRC Brakleen removing any oil or corrosion. If hard tap water was used to mix coolant (instead of the recommended distilled water), you may encounter stubborn deposits around the coolant inlet. Use a soft brush to remove them.
- Next, use a 10mm socket wrench to remove the three bolts anchoring the oil cooler to the oil filter mount.
- Remove the oil cooler from the oil filter housing.
- Use a metal pick to remove the oil cooler gasket.
- Use CRC Brakleen to thoroughly clean the oil filter housing and oil cooler surfaces.
- Install new gaskets in both the oil filter housing and oil cooler. Press them in with your fingers making sure they are seated correctly.
Reassembling the BMW N52 oil filter housing is very straightforward. It is simply the reverse of the above steps with no special procedures. We have included a handy checklist that shows the exact reassembly steps with important torque values for the mounting bolts.
KEYWORD REASSEMBLY Checklist
- Install the oil cooler back onto the filter housing and torque the mounting bolts to 25 Nm (18 ft-lb).
- Install the oil filter mount back onto the cylinder head and torque the mounting bolts to 25 Nm (18 ft-lb).
- Install the thermostat coolant hose back onto the cylinder head and torque the mounting bolts to 10 Nm (7 ft-lb).
- Plug the cylinder head coolant temperature sensor back in.
- Reconnect the coolant hose to the oil cooler and tighten its clamp.
- Plug the oil pressure sensor back in to the oil filter housing.
- Reinstall the oil filter and torque the filter cap to 25 Nm (18 ft-lb).
- Install the plastic protective cap back onto the oil cooler.
- Top off the engine coolant.
- Run the engine for a few minutes and confirm the=re are no leaks in the coolant hoses and gaskets.
- Check the engine oil and top off if necessary.
- Let the engine cool and check the coolant level again. Top off if necessary.