BMW E61 Turbo Replacement - Pulling the N54, and Stripping the Engine

Once all the electrical and plumbing was out of the way, and the exhaust, heat shields, driveshafts and drive axles removed, it was time to pull the engine. I initially planned to leave the transmission in the car, but a leaking rear transaxle seal made me decide to pull it out with the motor. We hooked up the engine hoist to a load balancing beam so that we could easily change the lift point with respect to the center of gravity. This ended up working very well, and was essential when pulling the transmission with the engine. 

Starting the lift - this is as far as you can go without lowering the steering gear and engine support crossmember

One we started lifting, we quickly realized that the X-Drive front differential would not clear the steering box of the steering gear with the lower crossmember in the car. As soon as we dropped the crossmember - the engine and transmission popped forward without much effort.

Engine and transmission out of the car - complete with front differential and transaxle. Heavy combination.

Next step was to separate the engine from the transmission. We were having difficulty with this - and thought that we had left a bolt in - which ended up being the case. We actually snapped one of the aluminum bolts clean in the engine - the head was hidden behind a gusset on the side of the transmission - we didn't see it with the transmission resting close to the floor. This ended up not being an issue - as all these bolts need to be replaced anyway, and the broken bolt backed easily out of the hole - no problem extracting.

Transmission on a dolly with castors, steering rack and crossmember on the ground.

Beer time.

First order of business before putting the engine on the engine stand was to remove the rear crankshaft oil seal. I thought this had been leaking, but it turns out it was still sealing well at 185,000 km. I bought the new seal and will replace the seal anyway. You can see oil coming down from the top right of the head through the gap between the engine and the bellhousing - this oil was coming from the area of the rear turbo.  

This seal pops out easily with the assistance of a couple of screws drilled into the seal. 

Claw hammer to remove the seal using the screws

Old oil seal - oil grooves are still in reasonable condition. Will replace anyway.

Since all the fasteners on the block are going into aluminum, and my torque wrenches are about 25 years old - I decided to check and calibrate the torque wrenches before I took down my engine crane. I just clamped a small vice to the arm of the crane, and held the socket of the torque wrench in the vise. I then loaded the torque wrench using a 5 gallon bucket of water and steel weight - adding water until the torque wrench would click. I would then measure the weight of the bucket, and apply the factor of length to come up with the actual torque. My 1/2 torque wrench recalibrated nicely with a small adjustment, and I'm within about 2% of torque. My small 3/8 torque wrench seems to have lost it's linearity across the internal spring - I could not get it to 5% across the measurement range and discarded the wrench. Quick order to Amazon to get the Tekton 3/8 clicker torque wrench to get me through the job. 

 This morning I got onto removing the turbos from the block. This went pretty quickly without much hassle. One thing that I've noted with this whole process however - is that it's really handy to have a few different sets of torx and e-torx bits - because sometimes you need a long bit, sometimes you need a small short bit, just to fit into the limited spaces where you're working.

Short 1/4" drive torx bits to get into tight spaces. 

Long torx to get at the manifold bolts. 

 It took about 2 hours to strip everything off the right hand side of the engine, including the bearing support for the front right drive axle, and the differential from the other side.

 Two of the exhaust manifold studs stuck in the block with the E-Torx head broken off - needed to jam 2 nuts together to get these last two out.

Jamming 2 nuts together to remove last two exhaust studs.

 Oil stain on the front differential was coming from the top vent. I'll be replacing the vent along with the seals - already have the vent on order.

 Removing the pan was fairly quick - had to remove the power steering pump first.

Turbos, oil and cooling lines, differential and oil pan removed. 

 New problem encountered - looks like my head gasket is leaking oil from the front right corner of the motor. The area below the head gasket is wet, and I don't think it's come from anywhere else. With everything off the engine, especially the turbos, now is the time to do this.

More to follow. I'll start with replacing the front and rear main oil seals, the oil pan gasket, and do the intake valve walnut blast. I'm researching what's involved in doing the head gasket now.....

Sources and Links

I hope you found this post useful. Feel free to ask questions in the comments section below. I answer all questions. If you're interested, you can help support this site by using the following links to Amazon.com in the United States. Turbo parts were supplied by Turner Motorsports. Other parts were supplied by Pelican, BMW Park Avenue in Brossard, and eEuroparts.