hello everyone .
i am new here, been checking the forum since a while, lot of usefull info there.

Here is my problem.
I have a 98 Grand Prix GT with the 3800 V6 engine.
when i drive most of time the engine is totally quiet no sound/noise at all.
and once in a while, i dont know why it start to make a weird whistle/rattle noise, like if something was touching the belt or if one of its pulley was loose.

The noise come from where the pulley are, like if one of them has a bad bearing(if there one in these thing), it do sound like a iron pulley loose.

I just cant seem to find if that is one of the pulley or wich one it is if it is the case or what to do .

When it do it i can drive and sometime its loud and sometime it get less loud then no more noise.

My belt is used pretty much some said it could be the problem if some water get in it, but well i dont think it would make a iron kind noise. When car is cold and i start it usually wont do it.

Also it seem to come more from the front/lower of the car/engine, even if i set the car in park position it still make it. Need to drive around so it stop, even if i stay in the park and speed it up a bit it keep doing it.

Also the engine been repalced by a GM genuine one in past, old one blown because of coolant leak.
For the trans i dont know, i wasnt its owner when this happened. engine is around 65k miles, the car is around 130k miles(so the tranny probably is 130k miles too) but it dosent seem to come from the trans...

Thanks for the help

Mathieu

Ok heres an Update
I started the car this morning, it was cold and making the noise.it come from the A/C compressor/water pump area.

I found that if i set the fan speed selector for the heater to 1 or higher (not to A/C setting) the noise stop, and as soon as i set it to off the noise come again.

I guess it is the water pump?

If it's a squeaky belt, spray brake cleaner on it to see if it goes away...if it does, replace belt. IF it doesn't, it's most likely an idler or tensioner pulley. Start by taking the belt off after you do the first test, and wiggle all the pulleys for play, then listen to hear if they grind when you spin them.

__________________
GreenBastardPerformance2000 GTP Coupe (the green bastard)
XP, Pacesetters, LS1 TB & MAF,MSD System, P&P LIM, P&P GenV w/ 3.2, 3.0, 2.8, Devil'sOwn Injected 100% Methanol,PowerTuned, TripleEdge Trans w/3.29's
12.92 @ 105mph

ok, am gonna test this on the next day.
Thanks you very much