Annoying Belt Squeal

[DaveB]

Hi all,

Apologies I know this has been asked before but getting nowhere...

Just changed timing belt, and replaced all accessory belts at the same time because I had some squealing at startup. Now, though, it's REALLY bad, and won't go away until I've done a couple of minutes of driving, then rev'd beyond 3,000 and let off the accelerator.

All new belts, various degrees of tension (but fairly tight for what I'd like).

How have people solved belt squeal?

I've had this issue with several stageas now, and I don't know what the common element is. I suspect it's glycol on the belts from filling the radiator. VERY frustrating! I've had the car back from workshops after 100,000K services and it's had the problem; I've had an engine rebuilt with new belts and same issue; my friends cars have it bad... pulling my hair out with this one.

I've tried:

- spraying water on the belts, both stopped and while running

- spraying water/detergent on the belts, both stopped and while running

- brake/parts cleaner (good old carburettor cleaner, dissolves most things)

- tightening belts

- loosening belts

- changing engines (not to fix belt squeal, but it didn't help)

- rain dance

So annoying, after doing so much work over the weekend to replace timing belt, to then have to drive around in what sounds like the loudest mouse choir on wheels.

Any ideas which I haven't already tried would be welcome.

cheers

DaveB

[import_zone]

when i was working as a tech a technique we used was slight emery tape/sand paper, and lightly apply to the grove section of the belt while running, but it would be slightly harder on our cars due to the viscous fan, so may want to take them off and give them a very light going over.

other thing you may want to check is your turbo nuts to make sure the turbo isn't loose i know this can cause a similar noise to a loose belt but thats obviously only happens when on boost.

if not double check belts and make sure they are the correct sizes for the car.

just a couple of tips. but without hearing noise it can be hard to diagnose and do fixes.

[DaveB]

Thanks Michael. I suppose I could record the noise but if you just imagine a really loud belt squeal, that is constant. Revving the engine makes it louder. If I spray some water on the belts at the moment, it will go away for a few seconds.

The sandpaper on the grooves sounds interesting; it would flatten out the peaks a bit and make the belt sit potentially lower. I might give that a go. I plan to get some CRC brand belt grip and try that tonight. If that fails (and I'm thinking it will) then I will try the light sanding. RB25's have a viscous fan too so I might have to take that off again.

[Hertz Donut]

I used Belt Grip on my Commodore once, it just made a mess of the bay and caused the engine to start throwing belts. Never again.

I'd recommend trying to find the core issue. When you say you replaced the engine did you carry over any ancillaries from the old engine, like idler pulleys etc?

[DaveB]

Thanks Hertz... Commodore's have serpentine belts don't they? I don't think they're meant to take belt grip? Probably my experience will be the same as yours knowing my luck however... thanks for the warning

Yes, the idler pulley was probably carried over by the workshop.

However, the squeal gets worse/comes back when either:

- AC clutch engages (AC belt)

- fan comes on (alternator/water pump belt)

- I turn approaching full-lock (power steering belt)

ie. all belts are affected.

[DaveB]

Well, spray on belt grip didn't work. Think I'll swap back to the old belts tonight, after checking aircon tensioner pulley for alignment.

[66yostagea]

I have 3 stags and they all have done it at various times. It's an RB thing, all part of Hirohito's revenge.

Just do one belt at a time.

[DaveB]

I have 3 stags and they all have done it at various times. It's an RB thing, all part of Hirohito's revenge.

Just do one belt at a time.

Thanks, perhaps tonight I'll pull them all off again, and then try new and old one at a time, and run it as I add each belt to find out if it squeals.

[Jezboosted]

An old trick that used to be done in car yards was to grab a candle and rub it on the belt on the faces that contact the pulley.

[DaveB]

Well, just finished replacing the valve seals and replacing all the belts. Pulling them all off and testing them one at a time I think is the way to go for me in the future. It's finally quiet! Water pump/alternator belt was the worst offender. Had to put a fair bit of tension on it. Can't quite play low E on it so hopefully it's not tooo tight.