I have a very hard to find problem. Hoping some one can help PLEASE....

[milaca_mike]

Hi, I'm hoping someone can help me with this growing problem. I have a 2000 GP GT with the 3800 along with a very hard to find problem. I have what sounds like a whistle that comes and goes along with my Horsepower When the noise is present I have noticeably less power and when I dont have the noise the power is there. I ran the engine with the belt off and the noise was gone all I heard was pure power. My friend was following next to me in his car and could here the noise at 70mph. Can anyone help me......

P.S. when I have the air on it's really bad, (sounds like something is really dragging the engine).

[richtazz]

sounds like a bad alternator bearing to me. Take the belt off and spin the alternator by hand, if it squeaks or feels gritty when you spin it, that's the problem. If not, try each belt driven accessory until you find one that drags, and that's what you need to replace.

[milaca_mike]

Yeah see thats why this is such a hard to find problem because I've allready replaced to alternator and everything else seems to spin fine. the only thing I would question would be to belt tensioner. If that goes bad could that cause a drag or would the belt just slip past it?

[Irish1968]

Some metioned the alternator bearing might be your problem? I myself have had alternator bearing problems, has brought my car to a dead stop and seize it from turning over. But in your case, now its just a guess at the obvious, it is worse when you air conditioning is on. So..when you try to turn the pulley by hand, as you later mentioned with the belt off as you did with the rest, it turned freely. Now...here is a thought.....was the compressor clutch ingaged when you tried to turn it, becuase it always turns freely until the temperature control unit turns on the clutch and engages the compressor. I have been informed many times that it does this even when the air is not turned on, to keep the seals from drying out when not in use, but only for a minute or so...not sure. Don't quote me, but if worse when the air is on, might be the compressor. Also check to see if the all pulleys are secure, had my alternator pulley come loose, made a hell of a noise!!!!