135 Fuel System Woes

[emongoose]

Thought I'd share my experience. 06/08 build 135 now has about 10k miles. The timeline below is affected by my desire to have the dealership provide a loaner (subject to availability) while my car is in the shop. BTW... I've been in enough loaners now that if anyone would like an opinion of an '09 335 coupe, an '09 335xi, an '09 X6, an '09 528i or a '07 328i just let me know.


Week 0 - Took car in for hard start issues. Diagnosed as bad fuel pressure regulator. Part ordered.

Week 1 - Regulator installed. Drive home fine. Two days later (first time to drive it again, it took twice as long to start up). Called dealership.

Week 2 - Dealership sends fresh data to engineers (or level 2 techs???) to analyze and make repair recommendation. Diagnosed as bad HPFP (go figure). Part ordered.

Week 3 - HPFP installed. Starts great now! Fuel gauge won't read above 2/3 full... accurate below that.

Week 4 - Diagnosed as a bad fuel level sensor. I believe they told me that the sensor came with the replaced fuel pressure regulator, so the new one they had put on was bad. Part ordered.

Week 5 - Car in to have fuel level sensor replaced. Once tech had the car apart, saw that the new part in the box had a piece broken on it. Had to overnight another part. Tech replace the sensor the next day... saw that the gauge had moved, so it's fixed, right?

Week 5 1/2 - Thought it made sense to stop by the gas station on Saturday and top off the tank to verify that the gauge function is back to normal. Gauge read around 2/3 full... anticipating putting in about 5 gallons, right? Hmmmm.... only 2.3 gallons go in. Start the car, gauge snap to 3/4 full. Looking forward to another trip to the dealership next week. Heading to get our hair cut, the car starts to buck and sputter. Wife wants me off the road... asking me to pull into a drive somewhere... as the road is under construction and down to two lanes. I don't think so. If this bit@# is going to die, we'll push it off the road.Take her to the salon, and drive the mile back to the dealership, knowing full well the service department is not open today. Sales manager greets me at the front door (really nice guy), and I explain. He tries to get a hold of the service advisor to check on availability of a loaner, but gets his vmail (the SA was out coaching his son's football team, and understandably didn't have his cell with him). My sales guy was also there (also a really nice guy), and after we waited a bit to hear back from the service advisor, he gave me his car, and they moved my car inside.

Week 6 - Swapped out the sales guy's car for a loaner on Monday (back in the 335i coupe. Tech's scratching their heads. Turns out a vacuum hose on the pressure regulator came loose on the last service, and once reconnected, the fuel gauge reads correctly (they took it to the gas station to top it off just to be sure this time). Diagnosis on the rough engine points to a "stuck fuel vapor flap", which caused raw fuel to fill the charcoal vapor canister. I don't know how this would cause the engine to run rough, other than guessing that sensors in the vapor system were going crazy, and the ECU was going ape s#!t trying to compensate. Oh yeah.... parts ordered.

Week 6 1/2 - So I'm comfortably cruising in an '09 335 coupe till Thursday or Friday until they can complete repairs. On the bright side... having all of these "test drives" validates that I made the best choice for my personal tests in getting the 135 (ok... lets just ignore the technical issues).

The "stuck flap" issue was described as "a new issue we've been seeing lately". Has anyone else encountered this, or heard of this? I didn't see any postings when searching "Vapor Canister"... and I know if there are issues we are the first to complain! I hope this is not the new "HPFP problem".

[jeremyc74]

Damn that sucks. Hopefully they've got it straightened out now. At least it sounds like your dealership is making a reasonable effort to take care of you.