Cooling Fan Problems Please Help
Thread Starter
Instructor
Joined: Sep 1999
Posts: 181
Likes: 0
From: Lipan,Texas
Cooling Fan Problems Please Help
I have a 89 Vette with 39,000 miles , Im having a problem with the cooling
fan running when I start the car (cold start) and then the car will idle rough with the check engine light flashing, when it gets up to tempature the fan will shut off engine light goes off and the engine runs fine.
Thanks
fan running when I start the car (cold start) and then the car will idle rough with the check engine light flashing, when it gets up to tempature the fan will shut off engine light goes off and the engine runs fine.
Thanks
Last edited by Mr Mojo; Jul 27, 2004 at 07:26 PM. Reason: Sig pic too large
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
The cooling fan is controlled by the ECM which turns on the fan when the engine coolant sensor under the MAF on the front of the block tells it that the temp is 228F. The a/f is also adjusted according in part to the engine temp. I suspect that you have a defective temperature sensor. You can check this out with a scan tool and see what this sensor is relaying to the ECM. With the engine cold, the sensor should not say its 228F. Both the idling quality and the fan being on could be caused by a defective coolant sensor or its wiring harness plug which I have seen go bad.
With jfb. However *I* would think step one, would be to see what code the "check engine light" set.
