[blazerex]

Hey everyone I'm new to the forums and BMW's in general and I've been having a number of issues with my car. I drive a 2006 e90 330i with 74k miles.

The car has a really rough idle in the morning sometimes, the RPMs jump all over the place for about 30 seconds and the car will either stall or the engine's fan will come on full speed and the temperature light will come on. It goes straight to the red temp. symbol and goes into limp mode. I turn the car on and off a couple of times and it seems to fix the problem. This all happens before the car has even been put into gear. I know the motor isn't actually overheating because the car has been off the whole night and the engine is stone cold. It seems impossible for it to overheat within less than a minute of idling.

While I'm driving the car bucks and jerks like it's misfiring and the RPM's jump all over the place. The temp. symbol will come on and the car goes into limp mode. Again, turning the car on and off a couple times seems to fix the overheating problem, temporarily at least. Sometimes the car will randomly stall at a stop or coming to a stop.

Some more random problems:
-AC blows really inconsistently, sometimes it's feels like a turbine in my face and other times it feels like someone blowing through a straw. This seems to be linked to the rough idle.
-The window jam sensor came on all of a sudden. The car thought something was jamming the rear driver window when there was nothing there. This went away after a day and never came back.
-The passenger seatbelt sensor goes off all the time when no one is sitting in the seat.
-When the car starts to stutter badly while driving, the bluetooth will cut for a few seconds and come back.
-The low coolant light came on all of a sudden and I topped it off with some water and it went away. The strange thing is, I always check the level and it'd always be good. Its like the coolant level went down in a day.

My SES light is on and I've pulled the following codes: P0344, P0344*, P1554, P0102.

This is what I've gathered from doing a few searches:
P0344 : Camshaft Position Sensor "A" Circuit Intermittent
P0344*: No idea what this means
P1554: Sticky vanos
P0102: Mass Air Flow (MAF) Circuit Low Input

This is what I've done to try and resolve the issues:
-Removed and cleaned both camshaft solenoids with acetone and carb cleaner, and swapped them around. Done this twice over a couple of months.
-Replaced camshaft position sensors. (Only the sensors, not the tails.)
-Done an oil change with recommended weight motor oil.
-Ran a bottle of Seafoam through the system
-Temporarily swapped out the battery to see if that was the issue.

it seems like after I did each of these things, the car would run like a champ for a day or two and then the same problems would come up again. The SES light goes on and off without warning. Also, when the car starts to jerk, it is noticeably less powerful and the throttle response becomes really sluggish. I have a gut feeling this is all electrically related seeing as 2 of the codes has to do with a circuit and all sorts of sensors are giving false readings. I know my battery is weak because after 3 minutes of listening to the radio with the engine off, a yellow battery symbol shows up. Maybe the battery isn't giving enough/giving too much current causing the problems???

I love the car when it works properly but it sucks when it pulls this crap. Any help at all would be really appreciated, thanks again.

[nate5ks]

I had a very similar problem a couple of months ago. Similar codes, symptoms, everything. I spent weeks and hundreds of dollars throwing parts at it and getting shops to look at it to no avail. Over time it became apparent that bumps, especially sharp ones like speed bumps triggered the phenomenon. I looked for loose ground bolts and sure enough, one of the bolts (there are 2) that grounds the coils through brown wires into the top of the valve cover had stripped threads and was bouncing out of place when I drove over bumps or sometimes on its own and this would shut the engine off completely or cause it to misfire. Evidently this confuses the s*** out of the DME because the codes I got were sometimes totally unrelated and disappeared when I fixes the problem. My advice is follow the grounds before throwing parts. I spent several hundred over a long time trying to fix a problem caused by a bolt that cost me $0.57 at lowes.

[blazerex]

Found the loose ground and fixed the problem earlier today and it's running flawlessly. Thanks for the reply.

[nate5ks]

No problem! Glad it worked for you.

[UncleWede]

Even the sticky vanos went away? I've done two oil changes and still get that periodically.

[blazerex]

Ya everything went away, I don't think mine was actually "sticking" though. Maybe the solenoid wasn't getting a consistent current due to the unstable ground wire causing the computer to think it was sticking. Try taking them out soaking them in some car cleaner if you think they actually are physically sticking.

[LEDs]

Thank you thank you thank you so much nate5ks!! I know this is a super old thread but this grounding wire going to the valve cover gasket was something I would have never found if it wasn't for your post. I've spent countless time and money just as you mentioned trying to figure this out and your post helped me find this loose grounding wire. Even my local BMW shop was puzzled trying to figure it out! Can I send you a gift? You seriously helped me out!

Originally Posted by nate5ks

I had a very similar problem a couple of months ago. Similar codes, symptoms, everything. I spent weeks and hundreds of dollars throwing parts at it and getting shops to look at it to no avail. Over time it became apparent that bumps, especially sharp ones like speed bumps triggered the phenomenon. I looked for loose ground bolts and sure enough, one of the bolts (there are 2) that grounds the coils through brown wires into the top of the valve cover had stripped threads and was bouncing out of place when I drove over bumps or sometimes on its own and this would shut the engine off completely or cause it to misfire. Evidently this confuses the s*** out of the DME because the codes I got were sometimes totally unrelated and disappeared when I fixes the problem. My advice is follow the grounds before throwing parts. I spent several hundred over a long time trying to fix a problem caused by a bolt that cost me $0.57 at lowes.