98 Explorer "whine" and cuts off
My friend has a 98 Ford Explorer XLT that has developed a problem that we can't seem to get fixed. Most recently, a local garage replaced the belt on her engine, saying that it was worn and was the problem.
The problem is somewhat intermittent, and after a few days, it became apparent that the new belt (last replaced 4-5 years ago) wasn't fixing the problem.
The problem is two fold: There is a high-pitched "whine" (sort of like a hum moreso than a squealing belt) that is present. The AC on/off does not seem to make a difference, and the engine being cold or warm does not seem to matter either.
Anyway, what happens is that when this whine/hum is going on, it makes the engine idle rough, and will make it stop sometimes, like if you are in a parking lot or at a stoplight or something.
We've not been able to identify any set of components on/off that will make the problem reproduceable. The only thing I know of that's been done to this vehicle is the AC Compressor replaced a couple years ago, but this problem seems to have started sometime over the last several months, taking spells of coming & going, with no particular pattern.
The vehicle is a 98 Explorer XLT, PS PB AC Auto. 150K miles.