P0340 - Cam Position Sensor fault

[Bdc101]

I got in my car this afternoon and it felt very sluggish. It still got me where I needed to go, but it was very slow and I killed it trying to start off in 1st gear a couple of times (it is a manual trans). This was very sudden, it had not been sluggish or anything before this.



Pulled codes... P0340 plus the same code in the DME (using a Foxwell to pull the BMW code, I forget the number). No O2 codes or anything, just a couple of secondary air codes that have been around for years.



From numerous threads it appears that this indicates a bad intake or exhaust cam, and most of the threads describe an intake cam, so I found that I can get an intake cam position sensor tomorrow morning, unknown brand though.



I am supposed to drive two friends to a mountain biking/camping trip tomorrow, so of course it picks today to fail! But with a little luck I will have it running by lunchtime tomorrow.



Any other suggestions on things to check while I am just sitting here with the car? Is it possible that I am barking up the wrong tree? I can actually drive it, it's just very slow, and I imagine probably not particularly good to drive it right now. I'm just glad it doesn't appear to be anything actually broken, I was thinking to myself that it felt a lot like a timing problem as I was driving it, and kept thinking a bad timing chain tensioner must have caused the chain to skip a tooth.

[andrewwynn]

It's a miracle when you get an actual error from bad cps. Usually it's just random cylinder error.

You want OEM quality but you can possibly get a cheap local copy to hold you over. Which engine?

When DME finds any fault in the vanos it shuts down all the attempts to use it and it will drive like crap because the timing is off except for some very limited RPM.

[workingonit]

Originally Posted by andrewwynn

...You want OEM quality but you can possibly get a cheap local copy to hold you over....

I would like to be able to afford "Genuine BMW" parts (or the equivalent on my General Motors cars), but I'm willing to try parts of a lower-priced source, if my research makes a good case for its' quality:

Originally Posted by workingonit

from another post/thread https://xoutpost.com/1218667-post10.html I recently replaced a camshaft position sensor (exhaust) with a VEMO part (sub-division of Vaico, a European mfg. company). It's even stamped with GERMANY on it. Since it's easy to quickly replace, I figured I'd try a new supplier, just to find out if their quality is up to snuff. I can get a replacement overnight, if I need one, and since I always have a scantool hooked up, I should get a warning of imminent failure, beforehand. Of course, if the component is really hard to access/replace, if partial failure will instantly destroy the X5, or if no reasonable alternative to the "best" is available, then I'll defer to BMW or comparable-quality parts, always.

The exhaust cam position sensor I bought was: Camshaft Position RPM Sensor Fits BMW X3 X5 Z3 Z4 E46 E39 1.6-4.8L ti 1994-2012
Brand: Vemo

$42.55, from Amazon

Edit: I didn't pay $43 for it back in December, because it was listed at $22.35 back then. Which was a considerable difference! For $43, I might consider using a VNE sensor from FCPEuro for $28, now. But, you're looking locally for a crank sensor, which is a different matter, altogether.


It's never given me a hint of a problem since installation seven month ago, so maybe I got a good one? I'm also currently using a cheapo MAF sensor ($23), that seems to have solved my former lean codes problem, without breaking the bank. Next up: replacing brake pad wear sensors that go on and off every two months (on practically new pads).

[X5chemist]

Originally Posted by andrewwynn

It's a miracle when you get an actual error from bad cps. Usually it's just random cylinder error.

Might as well add cam sensors to my maintenance list.

[Bdc101]

Good to know, that is what I am experiencing. My car is a 2003 3.0. Hopefully the cheap part works at least for a little while.

[Nolimite39]

I just closed the loop at the connector for my break pad wear sensors on my E39 after the connector crumbled in my hands.

[Bdc101]

NAPA was able to get me a part -- unsure of brand but I am swapping it in now. Hopefully this sensor will get me to the trailhead and back. Then I can replace it with a sensor with Ze German Engineering later on.

[Bdc101]

Part went in and appeared to fix the problem! I still need to reset the code but the car has guts again when I drove it around the block. Booyah!

[Bdc101]

My car did the 400+ mile roadtrip no problem, carrying as many as five guys and five mountain bikes and a big roof box.



Also, I noticed later that I think I caused the problem myself. When I did the OFHG and VANOS hose around the beginning of the year, it looks like I had pinched the cam position sensor wire. It was hard to get the wire out, and then after I looked at it closely the wire itself was definitely pinched and deformed. Doesn't look like I broke the outer sheath, but internally it looks like it might be shorted or broken. Lesson learned.

[80stech]

That is really good information. I've seen that many times were a wire is damaged and looks OK but really isn't. Also a pinched wire can put strain on the connections causing problems.