BMW M3 idles ruff

Tiny
BALL_OF_FIRE
  • MEMBER
  • BMW M3
I own a 1997 bmw m3 with automatic trans. The car runs great for the most part but when I start it up after a night of sitting it idles ruff for a few minutes then it's fine after that. The car does not really idle ruff if I start it a couple hours later either. So what do you think is the cause for ruff idle :(?
Saturday, October 27th, 2007 AT 1:24 AM

4 Replies

Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
My guess is the electronic coolant temp sensor.
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Saturday, October 27th, 2007 AT 9:26 AM
Tiny
BALL_OF_FIRE
  • MEMBER
  • 2 POSTS
It does have a message to check coolant level but it's full, I never would have thought it was a coolant sensor causing the ruff idle. Can you tell me why the coolant sensor is the cause?
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Saturday, October 27th, 2007 AT 11:32 AM
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
On today's cars it acts much like the old choke on caburators! This is not the level sensor on the recovery bottle, it's usually on the block or head.
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Saturday, October 27th, 2007 AT 3:55 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Also, try loooking at the air intake boot, and check for vacuum leaks. Please let us know, thanks for visiting 2carpros. Com
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Thursday, November 1st, 2007 AT 11:09 AM

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