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 :(?
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Saturday, October 27th, 2007 AT 1:24 AM
4 Replies
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
BALL_OF_FIRE
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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
MERLIN2021
MECHANIC
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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
KEN L
MASTER CERTIFIED MECHANIC
48,363 POSTS
Also, try loooking at the air intake boot, and check for vacuum leaks. Please let us know, thanks for visiting 2carpros. Com