intermittent rough idle
Hey all,
This doesn't seem to be a huge deal as of now because i've only noticed it a few times. I don't know if my mind is playing tricks on me but I've only noticed it more recently on cold mornings.
Scenario:
Start the car and back out of garage, pull out of driveway and sit at first light (~less than 1 min from starting vehicle)
Idle on startup is approx 1krpm, settling down to a typical 750
At this light some mornings recently the idle every so often but consistently (5-6 seconds apart) while waiting at the light drops down to ~500ish 1 time and then right back up to 750. You can feel it in the car when it hiccups.
On the mornings it does this, I take off from the light and have about 5 minutes straight of driving without stops.
Once the car is warmed up, I can not replicate the issue.
Clutch in while coasting steady 750.
Idle at next stop light steady 750.
Sit in parking lot at work steady 750.
Car drives normal, no loss of power, no SES, runs through the rev's completely fine. Took it for a spirited drive yesterday on lunch, 3-5k rpm, 30 minutes or so on and off. Not one weird noise, slip, surge, or anything out of the ordinary. No idle issue at any point 60 degree's at the time of the drive.
I'm assuming that if it were a vacuum leak it wouldn't go away after it warms up. Not sure how the DISA behaves when going bad but also seems like it wouldn't just decide to work when warm.
Thoughts?
[2008 E90 M3 6SPD Jerez Black]
[2005 E83 X3 6SPD Black Sapphire Metallic]
[2003 E46 330i 6SPD ZHP Sedan Imola Red]
[1995 E36 325is 5SPD Black]
Reply With Quote
Originally Posted by san
