rough idle

[snowsedan04]

Lately there has been an uneven rpm at idle in my '04 325xi. Seems to fluctuate from about 1100 to about 1400, then settles down. I've been using 93 octane from Sunoco, so I don't think the gas is an issue. Maybe the problem stems from the fact that it's so friggin cold outside and that the drive to my ferry commute (about 15-20 minutes each way) means that as soon as she's really warmed up I shut her down. That can't help, but anyone know if I should check something else? I'm considering a fuel additive in case some water is in the tank.

 

[bmwrocks]

If you go from a warm garage to the frigid outdoors, then condensation could be an issue. It won't hurt to try some dry gas and see if it helps.

Bad gas is a possibility too, don't discount that. Try another tankful.

And don't rule out a visit to your dealer if it persists. They can hook it up and see if anything is out of order.....

Good luck.

 

[frolf]

sometimes dirty injectors can cause a rough idle, temperature can when you first start (see warm up thread on how my engine acts).

also i know Tom had an issue with his car with 93 octane and i think he runs 91 now. kind of strange, i run 93 and/or 92 and am fine.

 

[snowsedan04]

Thanks for the input guys. I might try some dry gas. If that doesn't work, maybe the dealer can hook it up to the computer and see what's what. I would wait for warm weather to see if it goes away, but the forecast is not looking good.

 

[Steve Neu]

also i know Tom had an issue with his car with 93 octane and i think he runs 91 now. kind of strange, i run 93 and/or 92 and am fine.

Just how would octane make a difference here? As far as I know octane relates to anti-knock properties.

Steve