Taking apart a blown BMW N55 Engine

After spending the last few weeks removing the N55 engine from my BMW 335i, I’m finally taking it apart so that we can see what has been causing that horrendous knock and how much will my wallet be hurting after this project. Check out the playlist on this car to get caught up if you’re new here! Let’s get to it!

How To Remove BMW N55 Engine from BMW 335i

Hey Guys and welcome back to another video and this is a long one! In this video I will be removing the BMW N55 engine out of my BMW 335i e92 coupe. I recommend checking out my previous videos on this car as they explain a lot of what is going on and why I’m removing the engine. I do skip over some of the parts, but most of the big stuff is included. I hope you enjoy and give this video a like!

As I’m not a BMW mechanic and I do this just for fun, so I ran into a few issues along the way. Some of these really were easy to solve, but required tools I didn’t have and some required some thinking even when I did have the right tools. I’ve learned a lot along the way and I think this is one of the best ways to get very familiar with your project car.

I started this project with some safety in mind as I’d be crawling underneath the car, so the very first thing I did was disconnect the battery that way I don’t chance it with the ECU, catch something on fire or short something out in general. After putting the cars on jack stands, I got busy with removing the interior air filter and both lower and upper section of housing that hold it in place.  I then removed the trailing links with just a couple of bolts and proceeded to remove the intake filter housing, the cowl panel cover and the clean air pipe. Once all of these items were removed, I had easy access to the intake manifold that’s held in by 7 nuts and a screw. Before I pulled it out, I made sure to unplug all of the connectors on the ECU and move the wires out of the way. Then it just pulls out. Don’t forget to disconnect the vacuum line at the bottom as well so it doesn’t break on you! The car has been treating me nicely thus far and I was excited to keep wrenching. I had music playing in the background and it was just me and the car.

My next mission was to drain it of as many liquids as possible. I drained the oil off camera and got to work on the coolant system. To get better access, I removed the fan cowl with just one bolt and go to draining the coolant from the bottom hose and once it was all drained, I took the expansion tank off as well. As I kept removing parts from the engine, I would disconnect and remove coolant lines along the way.

So far it has been basic mechanical wrenching and I’ve been enjoying it with no problems in sight!

Now that I have had plenty of space, I removed the serpentine belt which allowed me to remove the alternator as well as loosen the AC compressor. At the same time I removed the oil pipes making sure to catch any access oil spills.

At this point things have still been going pretty smooth, so I decided to tackle one of the harder parts of the engine removal. The removal of the axles or the output shafts, if your car is rear wheel drive, consider yourself lucky since you won’t have to deal with this royal pain in the butt! Now, undoing the bolts on track rod end, the wishbone, the trailing link and the anti-roll bar was a piece of cake compared to trying to take knock out the shaft out of the differential. Don’t be like me and try to follow BMW’s recommendation and just use a screw driver like I do here to pop them out. It’s definitely worth the cost of a seal.

Next I decided to tackle the removal of the catalytic converter. It looked very easy in the manual, so I figured it’d be out in an hour or so. At surprise to no one, I ran into some issues. The biggest issues I had here was that I could not separate the exhaust from the catalytic converter. I tried taking the bolts off with a socket, with some heat and plenty of WD-20, but at the end I had to cut them off with a grinder and break off the ones I couldn’t reach using an air hammer gun to separate the two pieces. I’m glad I’m not an exhaust guy in Midwest. What a nightmare that was. I then spent the next 20 minutes getting to the bolts on the engine support arm and the engine mount was out with the support arm. I was in the clear! Or so I thought. After removing the clamp, the cat was supposed to just come out.. but it never did. I eventually game up on it and removed the engine leaving it in place.

With all that extra space around the transmissions I was able to take the rest of the bolts out holding it to the engine. I can’t say they were easy, but using the CV joint extension and the short sockets. I was able to get all of them out in no time at all. I thought the engine is now ready to be separated from the transmission… but WAIT THERE WAS MORE!

After struggling for a bit, I had to do some research and I found out that since this is an automatic, the torque converter would be too large to come out with the transmission EVEN if it did separate which mine just wouldn’t. I decided to remove the 6 converter bolts and while I was under the car removing the bolts, I saw that propeller shaft was still attached to the differential, so I removed the 4 bolts and dropped the shaft down. Glad I caught that one before too much damage was done!

I then used a pry-bar to put some tension between the engine and the bell-housing hoping it would make it easier to separate.  Nothing was stopping me now! I was on a mission!