mikendogs

I have a 2001 GT 4.6L. It is stock except I have a K&N cold air intake. The engine runs normally in all driving conditions but "occasionally" I'll have an idle speed of 1500 to 2000 RPMs and during this time I can hear an audible "howl". This condition will correct itself within about 30 seconds and the idle returns to normal (700 RPMs) and at that point the "howl" goes away. I've cleaned the throttle body, MAF sensor, and all of the electrical connectors I can find. I have never gotten a check engine light and am thinking that a component is doing something wrong or a sensor is telling it to. Anyone have any ideas?

08'MustangDude

2001 GT, you also have a throttle cable, which has a return spring.
Clean and lubricate the assembly too. If you have Cruise, it will have
another cable, check the return strength of the spring. There should
also be an Idle Control Valve, which may also need checked, cleaned,
replaced...

sweetbeats

+1 to all that ^^^^

I had an issue with my 2001 GT where, when coming to a stop where the engine should drop down to idle, it would hang at a higher RPM like 1500-2000rpm, or other times it would stall when idling down. With the help of folks here I found a couple of significant vacuum leaks, but also determined the IACV was faulty. I new one was about $50 at my LAPS. Check those cables, check for vacuum leaks, and you can try cleaning the IACV but I found even after doing that I still had trouble and the new part did the trick.