New Owner, New Problems

[Estoril Lou]

Hi all,

I recently picked up an '02 4.6is, 66k on the clock. After an initial misfire was fixed upon pick-up, I made the 500 mile drive home w/out issue. I swapped in all new plugs and coils (Bosch) and the car was running fine. After a few days while driving the idle suddenly got rough and the following codes popped:

P0021 - Camshaft Position A sensor over-advanced
P1353 - Cyl 6 misfire
P1357 - Cyl 8 misfire

So, naturally, I swapped in 2 new cam position sensors, cleared the codes, fired it up, and the same codes popped.

Next plan is to drain the oil and take a peek at the timing chain guides. I've read a few threads on here already on possible fixes but none specifically for the 4.6is.

I will have access to better code-riding software this week to help pinpoint the problem, but Any help or speculation on what else to check would be appreciated! I have a feeling I will be spending a lot of time on here....

[Black-Forest]

From my understanding 4.6 won’t be different from the 4.4. If that helps

[Estoril Lou]

I read through X5only's thread here: https://xoutpost.com/bmw-sav-forums/...-misfires.html

He stated ultimately that his issue was caused by mistakenly swapping the cam position sensors. He has a 4.4 N62 whereas my 4.6 is a M52, and as far as I can tell, the sensors are identical (1 for each bank, located at the front).

I ran some rough diagnostics while the car idled, but haven't really dug in yet. Next step is to drain the oil and check for plastic bits. I've attached pictures of some of the diagnostics in case someone wants to tell me how bad it really is. I'm no technician. I'm just hoping the guides won't need to be replaced...







And since those pictures were boring:





I'll update this thread as I go to hopefully aid future x5'ers.

[Black-Forest]

Good looking 4.6 Engine is a M62. Do you get a rattle from the engine when you start it cold?