I have a 2000 GT convert. w/17000 mi.. When the air temp. is near freezing it will occasionally make a loud howling noise from somewhere in the engine compartment that only stops if I tap on the accelerator. It's done this since it was new but since it's stored winters I never took it in for service. I looked through the service bulletins but didn't have any luck. It kind of sounds like something is vibrating in the air intake. Also, not sure if this is related, but it will sometimes lunge at very slow speeds and it once backfired when first started. I thought the last problems were because the injectors were dirty from it sitting for long periods. Sorry this went on so long. Would appreciate any thought you might have. Thanks, Chumley

 

Is everything stock or do you have an aftermarket CAI?

 

Completely stock.

 

It's a mechanically worn IAC, read more about the problem here...