heavy belt squeal under boost?

[Outdorsman]

So far I've changed both the power steering, alternator, and timing belt. All should be tensioned within spec, but I get this loud squeal when I go under boost or high rpms. It doesn't do it on the low. I know the timing belt should be tensioned correctly, I measured it. I'm not sure about the alternator and powersteering but they are on there pretty tight. Its always when I hit boost. I can rev hard in neutral and nothing happens.


I read some posts about this issue but they said it was their alternator or harmonic balancer however, the car did not make this sound prior to the rebuild. Do the belts need to settle in or something?

I heard belt dressing can help but I don't want to cover up the problem.

 

[needbooost]

I had this problem a week ago, had to get the alternator way tighter than I ever would have thought.

 

[Outdorsman]

i'll bust out the pry bar or something then I guess . I lost the bolt that allows me to tighten it, not the one that attaches to the bracket.

 

[Lou98GSX]

are you sure its a belt squeal and not an exhaust leak . i have seen exhaust leaks make squealing noises .

 

[Outdorsman]

I don't think I have an exhaust leak, only leak I could think off is 1 bolt on the turbo which is stripped. Doubt it would cause it to squeal. Seems pretty tight.


Well ####, now that I looked up the bolt thing, turns out that could cause this.... I've always wanted a new turbo anyway .

 

[fstfbdy]

Im new to dsm's but not cars. Can't say Ive seen a belt squeel under only boost. As someone above said I have head a exh leak sound like a squeel. check for exh. soot around that loose/stripped bolt., etc..

 

[Outdorsman]

tomorrow I'm going to go get some high grade bolts from some bolt warehouse down here in vegas. Gonna get the bolt and nut just to see if it is the bolt that is causing this squealing sound. The turbo does have some side to side play.

 

[xxNocturnalxx]

I wouldn't be surprised if it's the alt belt.

 

[Outdorsman]

I don't understand why it only happens under boost tho? And in neutral it doesn't occur.

 

[GofaST4life]

I don't understand why it only happens under boost tho? And in neutral it doesn't occur.

Because under boost there is a load on the motor. Which then applies a load pressure to the pullies, thus causing them to slip/squeal.

When in neutral, its just revving and spinning the pullies.

 

[fenixnr]

If there is enough side to side shaft play the fins of the turbo could be hitting the housing.

 

[KewlWinter]

^ What he said. If this is a under boost only problem, I would start looking at turbo shaft play to make sure there is no housing contact going on.

 

[xxNocturnalxx]

I don't understand why it only happens under boost tho? And in neutral it doesn't occur.

Because the alt. is loaded more at higher RPMs.

 

[NC_Dirt_Racer]

Whatever you do don't ignore it. My very first DSM had a squeal that I though was a belt and I ignored it. Turned out to be the oil pump which I found out the hard way

 

[Outdorsman]

replaced turbo bolt, squealed a little bit. And turns out the alternator took a dump, voltage regulator. This car just doesn't want me to sell it. I went to visit a buyer and the battery died because of the alternator. 2 days prior, another buyer wanted to take a look and I had a flat and the turbo bolt issue causing the loud squeal. I just want to buy a truck, I'm done with turbo cars . Should have a new alternator soon.

 

[xxNocturnalxx]

Thank you very much

 

[Outdorsman]

still gettin the squeal, only when WOT is it noticeable, if I keep constant pressure on the gas pedal, you won't hear it but if I hit the floor, it squeals at about 4.5k rpms+. Changed the alternator and belt, fixed the bolt hole issue.

 

[Outdorsman]

belt tensioner on the timing belt is brand new. Its a gates model. There are no tensioners on the alt/pSteering besides the bolt and screw on the alternator which is on tight as it is.