Idle fluctuates when car is cold and then when is hot is still fluctuates not as much [Archive] - Bimmerfest - BMW Forums

: Idle fluctuates when car is cold and then when is hot is still fluctuates not as much

07-24-2012, 10:20 PM
Hello everyone,

Im new here, anyways I have an issue with my 2004 BMW 525i with 127k, the issue im having is that the idle fluctuates when is cold and then when is hot is still does it but not as much. I thought it was bad gas so I added an injector cleaner "lucas" but still same issue. the only error i get in my Idrive is increased emmissions but this message as been there before and never had a problem. What can it be?

07-25-2012, 05:16 AM
If you mean that the RPMs are steady around 600 but the car itself actually shakes a bit, then I just dealt with something very similar - see below.

07-25-2012, 10:05 AM
Thanx, can it also be because my spark plugs haven't been change since I purchase the car. When I purchase the car it had 82k and now has 127k. Nothing major has been done besides oil change, air filter and replacing brakes. Anything major needed to keep up with the maintenance

07-25-2012, 05:58 PM
Spark plugs are way overdue if they have never been changed - however I'd expect poor throttle response in addition to the rough idling if it was the plugs.

If you have the time, do the plugs yourself and save a ton of $$$ (even if its for the first time and you need to get the tools). I spent around $40 on factory-equivalent NGK plugs and another $40 for a nice spark plug socket and ratchet extensions. Still saved a few $100 if I would have had the dealer do it.

07-25-2012, 07:41 PM
I'm sort of having the same issue, but my idle would jump a bit and hunt at a stop. But my car is a 545 so would it be a related item as you mention above the disa part?

07-25-2012, 07:52 PM
increased emissions and fluctuating idle..... maybe O2 sensor?

If you have engine warnings in idrive have the codes read and you will get your best answer as to what the problem components are.