Trouble Codes

[Bimmer-Bob]

So, recently I've noticed that my car occasionally doesn't want to redline - or rather, that it seems to hit the limiter early, around 6500 RPM. Other times it's fine, up to about 7200 RPM (higher than stock because of the AA tune). Otherwise, no noticeable issues with drivability - starts fine, drives fine, etc. Occasionally slight uneven idle, but it's been that way a little bit ever since installing headers + off-road tune - seems to come and go. Anyway, I decided to hook up the old code reader, and this is what I got:

So, #1-3 and #5 could be a failing eccentric shaft sensor, a fairly common failure in these engines. Looks like a simple enough DIY, but almost $400 for the OE part.

#4 is worrisome, just because it's DME related, but it doesn't seem to be affecting operation of the vehicle in any way.

#6-7 have me stumped. I found another thread that mentioned these codes, and someone suspected VANOS, says they replaced the solenoids and the car drove better. I'm suspicious, because the VANOS solenoids have their own codes (2A82 and 2A87), neither of which show up above. Another forum showed these codes as "Engine shut-off time, Time counter Instrument Cluster - Time counter DME, Comparison" - I have no idea what that means, but it sounds like a disagreement somewhere, say between the DMEs internal clock and the one on the dash. And then it got me thinking, ever since my battery sat dead for a couple of weeks, I've had this weird CBS message at start-up, showing an engine oil change as overdue, counting down backwards into negative numbers (the oil was changed 7 months ago, with only about 1000 miles racked up since then):

Could that be related somehow? Like a weird timing mismatch?

Anyway, my plan in the immediate period is to clear the CBS reminder, clear the trouble codes, and see what happens, while mentally/financially preparing myself to replace the eccentric shaft sensor. But what else? Should I consider the VANOS solenoids? What confuses me is that the car really seems to be running fine - other than the drop in redline and occasionally uneven idle mentioned above.

Thoughts?

[Suhb]

I saw some users had vanos codes for eccentric shaft and vice versa. They work together after all.

Is this of any help?

[Bimmer-Bob]

The main thing I got out of this video was not to take my car to the dealership out of warranty! It looks like they're going to just keep throwing expensive parts and labor at the problem until they find something that sticks, lol.

Seriously, though, thanks for the input. I had considered VANOS solenoids as a possibility, but assumed that they would throw a code. I guess sometime they don't.

In my case, though, I actually am getting codes, and they're directing me to another common failure (i.e., the eccentric shaft sensor). My idle isn't that lumpy, but it's definitely not as smooth as it used to be - plus I've noticed a pretty strong smell of fuel at startup lately, like the engine is running rich, and there was quite a bit of smoke from the exhaust yesterday, too.

I cleared all the codes and reset the CBS reminder, as mentioned above, but one of the eccentric shaft sensor codes comes back immediately, and a second appears after the car is started. So far, all the other codes have not come back.

It's looking like I'm probably gonna have to plan to do this job pretty soon. It kind of sucks, cause I need to use the 1er to get to work at least a couple of days this week (my DD is down because I'm working on rebuilding the injectors) - obviously, I'd prefer to keep it out of service until this is addressed, but like I said, drivability mostly seems okay so far - hopefully it's not on the verge of total failure.

[Suhb]

At one point, I thought my eccentric shaft sensor was failing due to idle surges, and when slowing down to a stop, idle would dip nearly stalling the car. I was so sure it was the sensor and was ready to order a new one until I just removed the engine cover and unplugged the sensor. Absolutely no trace of oil in the plug.

I ended up removing my vanos solenoids and soaking them in maf cleaner which did help for a long while. I am probably going to swap out the solenoids as 100k maintenance since they do degrade and engine performance is reliant on it. Mind you, I never had a CEL or SES, and didn't read the codes, but I could feel the hesitations in the engine. I'll pull my codes this week and see if there's anything related to eccentric shaft or vanos.

Edit: I think it's very possible that when the solenoids are hiccuping and not retarding or advancing the timing on the camshaft properly, the eccentric camshaft sensor could get an improper reading. Oil in the plug would definitely point to a failing eccentric shaft though.

[Bimmer-Bob]

Originally Posted by Suhb

I was so sure it was the sensor and was ready to order a new one until I just removed the engine cover and unplugged the sensor. Absolutely no trace of oil in the plug.

I didn't realize the sensor could be checked without removing the valve cover -thanks for the tip!

[E91WAG3N]

Last year my car threw codes related to the coils and the eccentric shaft sensor. Coils were replaced and eccentric shaft sensor code didn't come back. I figure my eccentric shaft sensor will fail at some point in the not so distant future. I still get lumpy revs once in a while if I clutch in to a full stop from 50+ but no code is thrown.

I talked to a couple of folks at the dealership service department and they said 99% of the time uneven idle on these cars is due to coils and it's hardly ever the eccentric shaft sensor. I take that with a grain of salt considering most cars they see are fairly new, the coils likely just have a shorter lifespan than the sensor.

You've replaced all 6 coils already previously, correct?

[Bimmer-Bob]

Originally Posted by ubersteuer

Last year my car threw codes related to the coils and the eccentric shaft sensor. Coils were replaced and eccentric shaft sensor code didn't come back. I figure my eccentric shaft sensor will fail at some point in the not so distant future. I still get lumpy revs once in a while if I clutch in to a full stop from 50+ but no code is thrown.

I talked to a couple of folks at the dealership service department and they said 99% of the time uneven idle on these cars is due to coils and it's hardly ever the eccentric shaft sensor. I take that with a grain of salt considering most cars they see are fairly new, the coils likely just have a shorter lifespan than the sensor.

You've replaced all 6 coils already previously, correct?

Thanks for all the info. No, I've never replaced any of the coils - you think that's a better place to start, even though I wasn't getting any codes realted to the coils, and was getting the eccentric shaft sensor codes?

Speaking of, I need to re-check codes now that I've driven the car to and from work all week long. And I should probably eyeball the eccentric shaft sensor while I'm at it. It's just shitty timing - we just bought a house and I'm super busy getting ready to move, but I guess it'll just take a few minutes...

[Southjersey128]

I replaced my ess about six months ago. Light came on and stalled out when first started. Similar codes all related to the sensor. Slight amount of oil in the connector. Replaced the sensor, that fixed it. Word of advice, be sure to check the plastic 'plugs' on the bottom of the valve cover. The slightest bump to them can cause them to break off, like mine did. Then its another $400 for the valve cover too.

[Tworl28]

i replaced the eccentric shaft sensor on my car but was reading in my manual the other day and it said that the shaft sensor is convered under fed. emission warranty. Check with your local dealer it might save you some time and $

[Bimmer-Bob]

Originally Posted by Tworl28

i replaced the eccentric shaft sensor on my car but was reading in my manual the other day and it said that the shaft sensor is convered under fed. emission warranty. Check with your local dealer it might save you some time and $

Thanks for the tip.

Interesting thought - but it sounds like the kind of thing that would probably involve several trips back and forth to the dealer, with escalation to a regional rep, and finally to BMWNA, and possibly only end up with an offer to cover partial cost or something. The closest dealer to me is about 90 minutes away, which makes things a little more complicated.

Did you get it covered under warranty or dis you do the job yourself? And where did you see that it was covered? I looked in the warranty guide and it showed that the cats and the "engine control module (including onboard diagnostic system)" are covered by the 8-year/80K mile federal emission warranty.

[Tworl28]

I did the job myself about a year ago, but was recently flipping through the books in my BMW owners manual and am almost positive it said that sensor was covered. I would just double check, its on one of the pages in the back that shows what is covered under the fed. emission warranty. Quite the job just to replace a sensor ( have to remove valve cover ). I recommend checking the connector on top of the valve cover first. Sometimes they get caked in oil because the seal has gone bad. In my case it was a failed sensor. I also replaced the valve cover gasket and sensor seal.

[Suhb]

Didn't get a chance to read the codes but I swapped out my vanos solenoids and the car is purrring. All the idle dips and surges are completely gone. Car is feeling much more responsive.

[Bimmer-Bob]

Well, the car hasn't stranded me yet, but it continues to develop an uneven idle when warm, and keeps throwing eccentric shafts sensor codes (2A32, 2A34, 2A36, & 2 A37). I went ahead and ordered some parts - besides the eccentric shaft sensor and seal, I also picked up a VCG and Valvetronic motor gasket. I also decided to pick up some new plugs and coils - even though the engine only has 42K on it, it's 7 years old, and it's just one of those "while you're there" things.

If symptoms persist after the repair, I'll consider replacing the VANOS solenoids - I just didn't want to spend an extra $300-$400 on parts I might not even need.

[Bimmer-Bob]

Just to close the loop on this thread, I recently replaced the eccentric shaft sensor and gasket, valve cover gasket, and Valvetronic motor gasket. While I was there, I also replaced the spark plugs and ignition coils, and I also replaced the sport air filter in my Performance intake. Then I cleared all the codes.

There was a little bit of pucker factor when I went to press the start button (did I mess anything up?), but it started right up and felt nice and lively on the road. Once warmed up, the tach needle rose quickly all the way to redline when asked. The idle was improved, but not perfect - but it seems to be getting better with each drive. And after a couple days, so far no new codes.

[desertman123]

http://www.e90post.com/forums/showthread.php?t=900394

Glad you got it resolved. Might be worth it to check these out, I don't know how prevalent they actually are.

[Suhb]

My idle stumble came back. Left it alone for a couple weeks. Today I started to hear the throttle body open and close when I jab the throttle. There's a very noticeable throttle response lag from the throttle body opening and closing. What I feared has happened. Read the faults on the car and saw the Eccentric Shaft Sensor error codes.

2A31
2A33
2A35

Looks like I'm due a valve cover job.

[bionicbelly]

Originally Posted by desertman123

http://www.e90post.com/forums/showthread.php?t=900394

Glad you got it resolved. Might be worth it to check these out, I don't know how prevalent they actually are.

I just did the ESS on my car, and replaced all the gaskets and such while I was in there. When I cleaned the VANOS filters, they looked nothing like these. They were pretty clean with a few specks here and there.
Then, I was working on a friends E90, and she was having all kinds of vanos issues, pulled the filters, and the bottom one was COMPLETELY covered with shavings and gunk. Worse than the ones in the pictures from your thread.