I have a 2003 Mustang 3.8 liter. My problem is that if I am driving the car and the engine is cold the first time I stop at a light or stop sign or whatever the car makes a loud squeal for a half sec and then just dies. The car starts back up just fine and won't do it again until the next time I drive it and the motor is cold.

I cleaned out the idle air control valve replaced the belt and the idler pulley and air filter. Nothing has helped. I took the belt off and started the motor to make sure it wasnt a pulley problem and ofcourse it died without the belt on so I know it is not in the pulley system. Please help me. Please.

 

So this only happens ONCE each time the car is started cold, that is really interesting. You already tried what would seem sensible to the fix but hmm.

Have you felt any power loss? bogging, any dash lights, no other symptoms? long shot but you can check your injection system, clean o2 sensor. but these would be things that would be affecting you constantly. i havent done motor tech for a while so im rusty but just what came to my mind for now.

 

There is no power loss and I looked into O2 sensors and it would be a constant issue. When I removed the belt and started the car you could hear a constant but faint squealing but I couldnt pinpoint the location and then the first time I stop it makes a split second loud squeal and dies. If I could pinpoint the constant squeal then I think i could fix the problem but I dont know what would be squealing in the motor to make it cut off when its cold.

 

Well while you have the car running open the throttle. look at the pulleys and see if any of them make any unnecessary movement, lack of spinning, etc with the belt on.

but If there is still squealing without the belt then the only pulley that would be spinning is the crankshaft pulley.

you shouldnt be running the engine too long without the belt though because your water pump wouldnt be running

 

I know about not leaving the belt off for very long. The squeal happens soon after it starts so it isn't an issue. maybe the crank is getting bound up somehow. i dont know. i guess i will be asking around more. no one seems to know

 

Well if you find out the problem post it up, Im interested in what the cause is!