I need help with ideas how to get my serpentine belt quiet as I like my ride quiet and smooth. Only running 200km/300miles per year, to and from kids beach. The noise from serpentine belt is continous, sounds like a seagull on crack so I have to grease the serpentine belt EVERY day when bathmobile is used to be able driving the thing. A enthusiast car like this shall be absolute smooth and quiet because me and my kids love hearing the birds chirping along the LT1 song with t-top down, I keep brakes well maintained just for keeping them quiet, every squeak is immediately adressed with new rubber bushings, hangers etc so you get the picture how this serpentine belt is driving me crazy.

Setup : 1984 z28 gen 3 with a pontiac 1994 LT1+4L60e. Generator moved to top of engine, AC pump removed but pulley kept for routing serpentine belt. Original serpentine belt.

Tested/checked points :
- New belts, quiet first year but then noisy EVERY time started.
- "greased" with starch powder (potato powder and then corn powder) according to a tip, works for 3 days then noise is back.
- "greased" every start with cooking oil on serpentine belt : start engine, open hood, pour cooking oil onto inside of running belt with oil can until quiet. Wipe stains. Swear.
- Serpentine belt not dry as it is greased every day, surprisingly dry for being greased every day, it should be clogged up.
- All pulleys run nice and smooth also under load.
- All pulleys aligned within 0.2mm.
- No slippage when generator charging/servo pump maxed.
- Continous noise with no change according to load from generator/servo pump.

So remaining/deficient factor is probably my move of the generator to top of engine causing a 180 rotation point for the serpentine belt but this new position is so good, generator is easy accessible, well coooled and it looks good so I really would like to keep generator there hence me asking here for good ideas what to do. Obvious it must be my combination of generator position/stretch on belt but my strategy was that it should adapt after time...and well it did but with features.

All ideas and tips appreciated.

*edit : misspelled header of this thread. Serpentine, serpentine, serpentine*

 

Forgot : All pulleys cleaned thouroghly when new belt is installed. Also tried clean everything using same belt without replacing. Result is quiet for 3-4 days then the seagulls are back.

 

Why have you not changed the belt? They are subject to wear if the V-grooves on the belt wear too thin and it will not seat in one of the pullies then it will squeal. This is especial true on pullies that have seen some wear on them.

Normally it almost always ends up being alignment. .2 mm is well within factory specs. You may want to look at the centerline of the accessory. You can have the pully close but if the error is an angle it will try to walk the belt off.

Some basic bullet points.

Have you replaced the tensioner? Not because it does not have tension. They can make almost the same noise as a belt. The tension can also put and angle on the belt that will cause the belt to squeal.

As the belt wears it can fill up the V's in the pulley so a newer belt does not fall into the groove as much as ride on top. This can be tuff to "dig out".

Pullies can wear out. If the V-grooves wear to wide the belt will not seat.

I am not a fan of putting anything the factory does not recommend on a belt. I think that stuff just hides the real issue and makes it so it will be a constant issue over the the years. I do use crayon just as a diagnoses tool. The crayon can be put on the left side or right side of the belt to see if the belt is trying to walk off the system.

Based on the above I would start with a new belt and tensioner, clean all the pullies with a wire brush (the wire brush will also scuff the surface) and start over from there. Most of the time that will fix the issue. If not, I would then us a stethoscope on every accessory and try to figure out the source of the squeal. I have seen bearing noise fake out mechanics into thinking they had a belt issue.

 

THIS. LITERALLY. SAVED. MY. LIFE. My belt got wet a week ago, and ever since it has had this CONSTANT EAR PIERCING squeal. I do doordash, so I spend ALOT of time in my car, driving around, and that RELENTLESS shriek was driving me INSANE!! I tried this baby powder trick, and HOLY SMOKES It works like a charm!!! I couldn't believe it!! You have improved my quality of life immensely and I didn't even have to spend any money!!





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