Hi,
As the title says, I have what sounds like rushing air at the base of the throttle body, the small opening with the idle control valve. It sounds like a vacuum leak, and when the ignition is turned off the rushing sound carries on for 1 to 2 more seconds. Is this normal for these engines. I have removed and cleaned the idle control valve and had a good look round but can't find anything untoward. The fuel consumption has increased a couple of MPG.
The Jeep is a 99 4.7 V8 Grand.
Any help most appreciated.
Thanks
Jon