[MM Performance]

Awesome DIY man! thanks for contributing to the community!

[Tim603]

Great work man, one of the better DIYs Ive seen

[hoopvillian]

I'm still dreading doing this job but at least now I know I can do it.

Thanks for the writeup.

[ihernandez7910]

Last Saturday - turbo winning started. looks like ill be using this soon!..

thanks for taking the time to put together something like this... greatly appreciated!

[aekdBMW]

Thanks again to moo snuckle for posting this guide. I just completed my turbo install over the weekend. Between your information and the links you posted I found everything necessary to complete the job. It certainly wasn't a walk in the park, but if you do your research and take your time its not that bad!

I had about 30 hours of time invested in this project. Half of that was actual wrench time and the other half was verifying torque specs, checking all hose connections, dealing with stubborn bolts, and re-reading all my documentation.

I have driven about 250 miles since putting the new turbos in and so far not a single issue. No leaks, no strange noises, and best of all no wastegate rattle!!

[arsonal]

more detailed than any other post ive seen, 12 hours is dedication. now you can pretty much do anything on n54

[Augster]

Great DIY! Used it to do my turbo replacement...

Ran into a snag, however. Oil supply leaks (gushes) at the front/rear turbo junction. Was there any trick or special procedure to joining the two supply lines together? It seems to be a simple press fit with just one bolt holding them against the engine block, but not directly keeping the two lines pressed together.

I installed all brand new O-rings which RealOEM states are the same for both coolant and supply lines, but knowing that RealOEM has some errors here and there, I'm no longer confident the correct part was used for this junction.

Since it took me a day to disassemble (taking it slow, lots of breathers due to a hot and humid day, and re-reading through the DIY), I don't want to try remover everything and reassemble the existing supply lines and would rather buy both new supply lines then carefully assemble them.

UPDATE:

I resolved the oil leak: the O-ring (which was brand new) had been cut all the way through; probably due to having to manhandle the hose fitting with a lot of force in order to get it to plug into the rear turbo hose female hose fitting. Since I reused all the hoses, I believe they were rigidly formed into their shapes due to the many years of high heat, thus had lost most of their flexibility making them difficult to manipulate them in reassembly if they were pre-installed on the turbos first. I ended up buying a brand new front turbo oil supply hose and instantly noticed how pliable it was.

So from my experiences, here are my suggestions for other turbo DIYer's:

1) For the front turbo, install its oil supply line to the rear turbo junction fitting first (which should already be plugged into the block), install and tighten the hold down bolt to the block, mount the front turbo and heat shield, and then attach the other end of the oil supply line to the turbo (lube all o-rings first!). There is enough room to put in the hold-down bolt and tighten it with a small torx bit wrench (I got a small ratcheting wrench for drive bits which has been extremely handy in tight confines). I had to still pre-install the oil supply hose to the rear turbo first because there just isn't enough room to install the hold down bolt by hand.

2) The power steering hose should be unbolted from the steering rack at the U-bend before swinging the rack out of the way; my rubber isolation mount broke in half (probably due to becoming brittle after many years) after I twisted the rack towards the driver's side and the dealer could not find any part number for it to provide me a replacement. I had to get a generic rubber isolation mount from a local hardware supply store.

3) Instead of unbolting the coolant hose running along the front of the subframe, you could just undo the quick disconnect at the driver's side frame-rail (which goes to the heater)... IF you manage to separate the connection as there are no leverage points to assist. These BMW coolant disconnects can be difficult to separate after all these years, but if you're lucky, it will save a ton of time trying to squeeze your hand and using itty bitty turns to remove and replace that pesky screw below the power steering pump as you would keep that coolant hose completely attached to the frame. The alternative is to wait until you can partially drop the subframe in order to gain more clearance to remove the screws.

4) For the turbo oil and coolant lines, the photos showing their removal are in the wrong order. Once you get that far though, it should be obvious on how to proceed.

5) When reinstalling the subframe, lift it into position but allow some clearance to install and tighten the engine mount bolts. Also, if you were unable to disconnect the coolant line going to the heater, you can attach the coolant to the subframe before lifting it all the way. This is the only time I needed a helper to assist by moving the driver's strut and steering rack out of the way while I lifted the subframe with a floor jack. I performed all the other R&R by myself.

[BeastMode335i]

Thanks for this..!! Going to use it to remove my downpipes since it has a lot of information leading up to them being removed..

[1nityrider]

This will be quite handy for me when the time comes, thanks!!

[Indo Rider]

Originally Posted by BeastMode335i

Thanks for this..!! Going to use it to remove my downpipes since it has a lot of information leading up to them being removed..

Just to make sure you know, no need to drop sub frame for down pipes. Just drop steering rack and you'll be fine.

[BeastMode335i]

Originally Posted by Indo Rider

Just to make sure you know, no need to drop sub frame for down pipes. Just drop steering rack and you'll be fine.

Thanks brother..!

[sirdaft1]

Excellent write up! Great contribution to the community.

[adidoman]

Great job with the pictures and detail. Does anyone know how to make that a pdf so it can be downloaded and the pictures don't get lost in the furture

[BeastMode335i]

Here's a very non professional/unedited version, please feel free to work your PDF magic if anyone would like to make it pretty lol...

[fmonteiro444]

How's this?

[sirdaft1]

Originally Posted by fmonteiro444

How's this?

moo snuckle should add this to the OP. Great PDF to have on hand/print out during a turbo replacement.

[chinko]

Wow this is impressive! Detailed steps, well explained and illustrated, I almost feel like I can tackle this even if I'm a beginner.

[BeastMode335i]

Using this and the other DIY right now to swap my turbos.. Ran out of light today, but right when I got to the fun part of the subframe being dropped lol..

[BeastMode335i]

At what point is it OK to start the car and check for leaks..?? Do as long as all coolant and oil lines and down pipes are connected, is that when..?? I didn't wanna install the mounts and subframe and then find I have a leak somewhere.

[Augster]

Originally Posted by BeastMode335i

At what point is it OK to start the car and check for leaks..?? Do as long as all coolant and oil lines and down pipes are connected, is that when..?? I didn't wanna install the mounts and subframe and then find I have a leak somewhere.

I just ensured all fluid lines (oil, coolant) were connected, left the DP's off, and cranked it up wearing ear-pro (hearing protection).

Let it run long enough to ensure there were no leaks and everything running smoothly.

[BeastMode335i]

Originally Posted by Augster

I just ensured all fluid lines (oil, coolant) were connected, left the DP's off, and cranked it up wearing ear-pro (hearing protection).

Let it run long enough to ensure there were no leaks and everything running smoothly.

Yeah I wasn't sure exactly of that extent, I ended up bolting the rack and subframe back as well.. Luckily no leaks and everythings working as it should but thanks for your input..

Also, thanks Rob@RBTurbo for helping me get back on the road brother, I appreciate it..!!

[Sertone777]

Wow this is extremely amazing ! A lot of heart went into doing this for us to see!