I have a 2001 mustang with a 3.8 v6. My fan is kicking on and off when the engine is cold. Also, my idle is at times fluctuating down and lot more than normal. I was thinking the IAC and maybe the coolant temp sendor? Not getting a check engine light so don't think there are any codes. Any thoughts?
Thanks for the quick reply. I will take it over to autozone and see if there any codes. I did notice the ac compressor did kick on. Not sure if I had it on defrost though. Seems wierd for the electric fan to be kicking on when the engine is cold.
Just went out and checked it out again. Getting a cold start issue as well. I replaced the battery a few days ago for the cold start issue and thought it was fixed. Alternator charging above 14vdc and cables look good. I replaced the spark plugs a couple of days ago chasing a drop off in fuel mileage. I guess I will replace the spark plug wires and the electronic ignition module (not sure what it is called). With the fan switch in the off position the electric fan in the engine does not come on so maybe not a problem. It did come on after I turned it to defrost and saw the ac compressor cycle after a little bit.
I did clean the IAC. Is that the same thing as the ISC? I will clean the MAF. I do have an aftermarket cold air intake and sensor but never had any problem. Car seems to idle ok if not in the defrost position. Still not bad in defrost but seems different from what I remember in the last couple of years. Right now I think I am troubleshooting a cold start issue and poor fuel economy. I was thinking a basic tune-up would be good for starters.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.