[335ilux]

Had a missfire on banks 1, 2, 3 and injector initialization bank 1 code pop up on my 07 335i. Had a bad vibration and went to reduced power mode. swapped plugs and coils with no improvement. computer had been replaced at some point (dosent have the typical mosfets like the older computer)
so I took it to the dealer and there telling me it is a spun bearing cause they found a "few" shavings in the oil. but no low oil pressure. in my past experience with GM motors, you spin a bearing and oil pressure drops off. o, and they quoted $25,000 to replace. really? I'm thinking injector problem still but would like more opinions on what to do next as there's no way I'm dropping 25k on a $9k car.

Get your oil analyzed and report back with results.

[DennisPacMo]

I've owned a N54 with a spun rod bearing. You'd know it. It has a rod knock and then howls when the bearing starts to spin.

[335ilux]

Originally Posted by DennisPacMo

I've owned a N54 with a spun rod bearing. You'd know it. It has a rod knock and then howls when the bearing starts to spin.

how did it act power wise when it happend?

[Boland01]

A spun bearing will cause a loud rod knock. As others have said, have the oil analyzed. I would also look at the oil filter and see if there are shiny bits of metal.

[DennisPacMo]

Originally Posted by 335ilux

how did it act power wise when it happend?

It had misfire and super knocking codes for that cylinder but drove ok. Lacked power a little.

[Fundguy1]

Blackstone. They analyze the shavings to tell you whats damaged.

[longnvu]

sounds like o2 sensor

[mxchris727]

Leaking injectors are the main cause of spun N54 bearings. The gas thins out the oil acting as a solvent.

[335ilux]

oil doesn't smell like gas. also only code being thrown is P10A5: injector initialization error (group 1) also has horrible miss fire but no missfire codes. but wile i wait on the oil analysis, what can cause that strange code? Can't seem to find much on it and bmw dealer just says "replace motor, 15k+10k in labor" I don't think replacing the motor alone is going to solve that P10A5 code.

[335ilux]

Well I went ahead and pulled the motor, there where obvious signs of bearing failure in the oil. so, the motor is out, picking up the replacment some time this week. other than bell housing bolts and exhaust gaskets what els should I or "must" replace? [IMG][/IMG]

[Jaronbwall]

That's a bummer man. Are you doing the work yourself? Just curious. It would be easier to install a single turbo now.. just saying. haha

[335ilux]

yes it did escalate quick lol. and I am doing the work my self, I wish I could afford a single turbo kit but that's not in the books right now, just going with some RB chra's for now. unless this would fit? lol

[335ilux]

injector index 2?

[335ilux]

can you spot the bad turbo lol
so i ordered some vtt stage ones

[Underground6t9]

I had a spun bearing cylinder 1, the bearing melted with the crank. It had a loud thicking sound around 2-3k rpms, other than the sound it drove great. I had the mother pulled as it was not salvageable and replaced it with another used motor. In the end it cost me 10k to fix. From what I gather leaking injectors diluted my oil causing the the bearing to spin. Keep and eye out for thos leaking injectors.

[DennisPacMo]

If you are saving this motor and just doing rod bearings, make sure you read the TIS info from BMW on rod bearing selection. I had to order all 4 types and return the two unused types of rod bearings. The laser etching that tells you what bearings you use is on the front of the first crankshaft counterweight.

[335ilux]

I'm picking up a used motor, 117k miles but supposed to be in good shape with 90 day warrenty. and not to far off from the actual mileage of the car it's self (108k)

and I'm pretty sure it was a bad injector that cause the whole problem, there index #2 in all 6 cylinders+the 108k miles on the car, also no records of them being changed at bmw.

all in all, with a few new parts + motor + upgraded turbos I should come in under 4k on the total install.

[Esixty1]

There is a list as long as your arm of stuff that could/should be replaced as part of the swap. You need to decide how long you are going to keep this bad boy, what you're prepared to spend and how much potential hassle you want to save yourself down the track by tending to some things that are easy to get to right now...

Think stuff like valve cover gasket, oil filter gasket, sump gasket, rear main seal, thermostat, how old is the water pump etc. Then there are all the one time use bolts that go with these things, many of which are aluminum. Do some research on injector o-ring seals...quite critical apparently. I've probably spent circa $1500 on all those bits and bobs.

It looks like you are very efficient at getting the thing out though, so if you need to go there again... I'm only planning on doing it once. Good luck!

[MiniXP]

Originally Posted by mxchris727

Leaking injectors are the main cause of spun N54 bearings. The gas thins out the oil acting as a solvent.

Do you have any source for this? I see people say this all over this forum, but have never seen conclusive evidence. Also, any shop I've asked doesn't believe that is the case.

I had a spun bearing, replaced the motor, but am still using the injectors from the previous motor. It's been 3 years now and I've sent multiple oil samples to blackstone, none of which have come back with excessive fuel in the oil.

[Underground6t9]

Originally Posted by MiniXP

Do you have any source for this? I see people say this all over this forum, but have never seen conclusive evidence. Also, any shop I've asked doesn't believe that is the case.

I had a spun bearing, replaced the motor, but am still using the injectors from the previous motor. It's been 3 years now and I've sent multiple oil samples to blackstone, none of which have come back with excessive fuel in the oil.

The shop that I had my work done belives that this was the case for my car. I did regular oil changes around 4-5k