The other day I heard a loud noise coming form my 1997 Ford Explorer. The only way to describe this noise was a loud whining (much like a weed-whacker at full throttle) I could not determine if it was coming form the engine compartment or the undecarriage.

After driving around the last several days it is still happening intermittantly but I was able to diagnose when it happens. It seems to ocurr once in a while when I rmeove my foot form the accelerator. When I hear the noise begininning it will immediately stop once I depress the accelerator pedal again.

It doesnt happen every time I remove my foot from the accelerator (only once in a while). AC is not in use when it happens and it does not affect the performance of the truck and I notice no change in RPMs - it sounds like a rush of air possibly.

Anyone have an idea?

 

If it's a high pitched whine, it could be the bearings going in your idler pully. I get this out of my taurus and freestar when the weather is cold outside. Got the same thing from my 96 and 01 Explorer Sports. They're cheap and easy to change.

 

someone told me it sound slike an exhaust leak because it goes away immediately once I hit the accelerator - does that sound right?

 

My noise/whine would always accur ag a given RPM. Normally within a 50-100 RPM range. Normally around the 2100 RPM range. No noise on eiter side of the 2100 RPM range. Normally an exhaust leak will provide either a ticking lifter type noise, or a hissing air leak noise.

 

Never noticed if it was happening at a given RPM or not. My fire dept mechanic looked at it yesterday and he said catalytic converter looks ok but he could not duplicate sound. He drove it around the building for about 15 minutes and nothing. On my way home from work today it happened once (in a 15 minute drive) and yes it sounds like an air leak but one definitely LOUD air leak ! - People turn their heads on the street if it happens when i drive by them