Help!!! Extremely Low Idle - BMW Forum

quinescence · 04-14-2009, 09:33 PM

I don't think this has anything to do with this but i replaced my stereo. (already aftermarket wiring) previous stereo ran fine. Installed a sub woofer and 1200 wt amp. Now when i start the car it idles at 500 or lower. I drove it around the block and i get full power and acceleration. It just doesn't stop dropping rpm at 750. Radio change could just be a coincidence. ICV maybe? bad control module? I'm at a loss here. When i pulled up back to the house the idle just dropped and i started the car again and it stayed at 500 rpm

witeshark · 04-15-2009, 12:07 AM

That may well be alternator drain.

quinescence · 04-15-2009, 12:12 PM

So obvious next step would be to check the alternator for operation? Or replace? I haven't played the stereo loud yet. But i did notice the car was a little better on cold start this morning. I went to pick up some oil and by the time i got back it was running bad again

witeshark · 04-15-2009, 12:29 PM

That's where I'd start.

quinescence · 04-15-2009, 08:24 PM

I changed the oil and she ran a little better still bouncing the idle just not choking at all. i checked the charge at the battery 12.56 off and 14 running. Everything is grounded to bare metal. I think it might be my tps or maybe the icv needs to be cleaned. didn't quite get to those today but tomorrow...

M3Dreamer · 04-16-2009, 04:43 PM

Yea I had my Alpine Stereo in my car and found that it did the same thing, I had a 1000W amp with 10" subs and found that it ran a little low on idle. Since then I took out the amp and subs and it runs good. The only thing is that I have a speaker on the drivers side that fades in and out. usually helps when I hit a bump there is a loose wire somewhere. I would double check your alternator, I think autozone or some autoshops will check your alternator for free. Good luck!