E90 CPS timing over retarded

[Bmwpower603]

My girlfriends 2006 e90 330xi with 140k threw a check engine light for cam shaft position sensor over timing on BOTH banks.

The same thing happens everytime. The vehicle rpms become erratic, will drop low, then the check engine light comes on. And the car goes into limp mode.

I cleared it. And it practically came right back after driving it.

After a week of driving and clearing the code. Only one code for bank 1 remains though. Not two.

My friend who has worked at BMW for a while told me to throw in 2 new vanos solenoids... So I bought 2 OEM ones. And have not yet installed them.

I was wondering, if this code does come back after installing these EXPENSIVE PARTS. Does that lean towards cam sensors at that point ?

heres a pic of the code

Keep in mind there was one for each bank before.

[TonyAngel]

Did your friend at BMW run a diagnostic scan using a BMW specific scan tool for you. "P" codes kicked out of a generic scanner can be pretty misleading, although the VANOS solenoids going bad or getting dirty is not uncommon. I'm surprised that your friend recommended their replacement rather than just trying to clean them first.

Assuming that all you are going on is the "P" codes, it still isn't unlikely that the solenoids are the source of your problem. I'd get a scan done with a BMW scan tool. If you are unwilling or unable to have that done, I'd pull your solenoids and clean them and see if the problem clears up. It isn't a very involved job.

BTW, how much did you pay for the solenoids? Eh, I suppose "expensive" is relative, but you can clean them and see if it helps. If it doesn't and you replace them with the new parts without having run a diagnostic with a BMW scan tool, it's a bit of a shot in the dark.

I mention getting the scan done because, although it is likely that your solenoids are bad or dirty, it's also possible that your VANOS system needs rebuilding. I haven't done this myself, yet, but I have read that the seals go bad at around 50k miles and it takes a while for symptoms to manifest.

[Bmwpower603]

Thank you for the reply. Very much appreciated.

To answer your question. The vanos solenoids were $160.00 each at BMW, with my discount. And I bought both of them. . I know I should get the problem properly diagnosed. (Wish I could do myself if I had good BMW diag software)

I realize I probably could clean them. And maybe have the problem come back. But I guess that is better than throwing $320.00 at the vehicle just to have the code come back.

My other question is. If it's is a cam position code. Why wouldn't my friend tell me to replace the cam senors? Wouldn't that be the cheapest route ?

As for the vanos rebuild. I would think the e90 would stay in limp mode 90% of the time of that were the case.

[TonyAngel]

It is likely that your friend advised you to change the soleniods because their going bad/getting dirty is pretty common and from what I've read, they can be responsible for a multitude of fault codes. They are easy to get to and clean as well. This is why many on this forum suggest a scan with a BMW scan tool. The generic "P" codes that you posted could be caused by a few different thing. I was doing some light reading through the Bentley manual a short time ago, and I believe that there was a laundry list of items that could cause the code you're referring to. Of course, the first thing the manual suggests is pulling the solenoids and cleaning them.

Pulling the solenoids and cleaning them really isn't a big deal at all and a good way to rule them out. Please, be aware that I am new to BMWs and am learning as I go, but if I recall, testing them isn't hard either and only requires the application of 12v to confirm that the plunger moves.

As for the E90 going into limp mode due to needing a VANOS rebuild, I really can't comment. From what I've read, the system seals are degraded at 50k miles and the symptoms that manifest range from being unnoticeable to going to limp mode. I do know that on my E90, I've had 2 problems that did not cause any lights to come on, so I'm not going to assume anything. First, I had a bad eccentric shaft sensor and only discovered it due to a recurring fault code (no lights) and I'm having the stop/bump problem with my transmission, which hasn't caused any lights to come on and has returned no fault codes.

As for the solenoids, I'd recommend doing them in a manner that would reduce the changes of dropping a part or bolt into the engine block. Lots of vids on the subject.

[SlackTube]

Before you go all batshit crazy chasing vanos/cam/timing faults you should check the oil filter. If the center insert of the oil filter cap is gone it will cause all sorts of issues and similar faults.
next step is vanos solenoids.
next step is Valve cover removal to see if there's broken vanos bolts or cam bearing ledge wear.

[Bmwpower603]

Before you go all batshit crazy chasing vanos/cam/timing faults you should check the oil filter. If the center insert of the oil filter cap is gone it will cause all sorts of issues and similar faults.
next step is vanos solenoids.
next step is Valve cover removal to see if there's broken vanos bolts or cam bearing ledge wear.

The cam code actually came on shortly after doing an oil change. .

When you say oil filter cap. Do you mean the mesh piece on the cap? Or the piece with the o ring on it?

I can check and make sure that the cap it in tact. ..

Edit:

Here's the problem. The cap / piece must have stuck to the old oil filter when I did the oil change.

[SlackTube]

Glad I could help

[Bmwpower603]

Glad I could help

I'm gonna beat myself up over that one.


Thank you very much for the diagnostic help.

***Cheers***