The other morning, I got in to my car, started it up and the car started idling so poorly that I was sure it would stall. It didn't stall and I drove straight to the dealer. The dealer said they had no loaners and they wouldn't even be able to look at the car for at least 72 hours, so I made an appointment for the 21st with a note to call if someone else cancelled their apointment in the mean time.

The car only seems to idle and run very rough until it's warmed up. For the rest of the day, it starts and runs just fine, then we repeat the process the next morning.

My biggest worry is that I'm doing further damage to the vehicle by continuing to drive it. With no loaner, I really don't have a choice. Any ideas what I might be up against?

There are no check control messages, only the yellow engine light in the instrument cluster is constantly illuminated:

 

From elsewhere:
"High Pressure Fuel Pump - Although there have been several other parts that have been routinely blamed and replaced, i.e. fuel injectors, spark plugs, ignition coils, the HPFP has been the most commonly replaced part when the N54 engine exhibits a rough idle on cold and warm starts, hesitation when accelerating and/or a sudden loss of power. These symptoms are usually accompanied by the illumination of the yellow check engine light and/or the "Engine Malfunction - Reduced Power" warning message appearing on the iDrive screen. "

Also from elsewhere (not same engine, but previous gen, I think.):
"if you have the m54 eng i would remove the idle control valve and check it for sticking. if it is ok, than i would disconnect the battery overnite with the cables touching each other. this is called a battery discharge. this is actuatly a BMW repair. this causes all the modulles to relearn itself. it has fixed many of cars for me.

what type fuel are you using. try a diff brand and octane and see what happens. some cars like 89 better than 91/93. i run 89 in my 325 due to better mpg and perf. i get 2-3 mog more on 89 than 93"

 

Hi there,

I have no check control messages on the iDrive screen, just the yellow check engine light and the problem only happens on cold start ups.

 

I have a 2008 535XiT and had the HPFP replaced May 2009. The failure started with rough starts in the morning and 2 dealers "fixed" the car by reprogramming it to latest BMW s/w until the car started throwing error codes and reducing engine power when the HPFP was about to go. If there is ANY chance this is the HPFP, the dealer should replace it since it is a known problem - although they probably won't since they have to go through BMWUSA for approval, leaving you with a $60K car that may die at any time.

Sorry to hear about your dealer not being able to look at the car for 72 hour and no loaner - and you not having any options. That guy would go out of business in NJ.

 

Yes, it's a bummer. I wanted to point out to the service advisor that BMW of Sterling's garage being so swamped should tell them something about the direction BMW's engeneering quality seems to be taking lately. Ugh. I hope being on the cancellation list helps me get in sooner.

The HPFP was already replaced about 7k miles ago. Fingers crossed that isn't the cause of this problem!

 

My HPFP was replaced today while at the dealer for rough running in the mornings. No idea whether this was coincidence or a result of the recall.

 

Is that the only thing they replaced and did it resolve the problem?

 

Check out my "Interesting 535i" thread. It sounds like the exact same thing I had, and the dealer replaced all six fuel injectors under the extended HPFP warranty. Could also be the coils.

I never had the rough running in the morning only with the fuel pump. It was rough or hesitating all the time. This morning roughness was far more extreme than the symptoms of the fuel pump going that I experienced before. It was almost like it was going to stall if I didn't mash the gas. And it vibrated terribly until the car warmed up.

I would think that a fuel pump going bad wouldn't be effected as much between cold and warm engine, as an injector or coil would be. Once the engine is warm, the injectors and coils operate much more easily, thus masking the problem.

 

As ADD says it could be the fuel pump, but if you have had it replaced it sounds like an injector or Coil pack.... Is there any smells like rotten eggs?

 

Dont drive your car and rent one in the meantime..