Shredding fan belts

[gbu]

Don't know if the mechanic has got a dodgey batch of serpentine belts or what the deal is, but this is about the third that has gone in in about 18 months. I can't see how else they would be shredding along the length of the belt, there is nothing for them to rub against.
Anyone?

 

[happy john]

Do you do alot of beach work? sand can do that but your drama is excessive apart from a misaligned pulley it must be one of of the above has the same person replaced the belts?if so take it elsewhere.

 

[doc]

Might be a silly question, but the tensioner bearing isn't seized is it?

 

[Old.Tony]

If the tensioner bearing isn't seized, maybe you have a neighbour who's pissed off with diesel clatter and is being really, really subtle.

I'd check both idler pulleys. One is just above the power steering pump on the right hand side of the motor (belt goes OVER it) and the other is just to the right of the alternator (belt goes UNDER it).

 

[gbu]

I can't see any idler pulleys. Just the tensioner. Everything going round and round like it should.

 

[gbu]

It's only the flat side of the belt that is getting damaged, and the tensioner pulley is the only thing that touches that side of the belt.

 

[gbu]

Here's the tensioner pulley, you can see the grooves worn into the flat side of the belt. There are only five pulleys on the front and no idlers. Might to replace it myself with a genuine nissan part and see how well it wears.

 

[gbu]

A better shot.

 

[gbu]

There is pitting across the face of the pulley. Don't think that should be causing it.

 

[Old.Tony]

I just went out to my car and had a look to see if there was something I could see that might be near enough to rub against the outside of the belt somewhere. Here's what I discovered.

1) There is a boost leak around the charge air hose where it attaches to the manifold.

2) I have oil all over my arm from 1)

3) There is nothing on my car that would get close even under strain to cause damage to the outside of the belt

4) The outside of my belt looks like it's hardly been touched. Yours looks like it's been rubbed to hell all over

I suspect your tensioner (which is an adjustable idler, there's another one on the smaller belt down the right-hand side of the vehicle) might not be spinning at the same RPM as the belt needs it to - I think it might stick now and again. Possibly grit or something in the bearings? The back of your belt looks like it anyway.

If you loosen the tensioner, pop the belt off and spin the tensioner wheel, it should move without any hesitation or grittiness at all.

 

[gbu]

The old charge air hoses are messy aren't they? Have you fitted a catch can?
Is there any way of repairing the tensioner pulley bearings or cleaning them, or do I just ditch it for a new one or wrecker part?

 

[Old.Tony]

I've never taken my pulley apart to know for certain, but some people here have used WD40's Silicone Spray which happens to be the very thing I'd try first on my car too.

I did have a catch can fitted, but I broke the measuring gauge on the side so I removed it. I'll put it back one day!

 

[gbu]

Are you able to find the part number for the bearings in the tensioner pulley? Just in case.
I want to get the workshop manual but not sure where to get it.

 

[Old.Tony]

The manual isn't revealing any Nissan part numbers. It just refers to the "idler pulley". It makes the same reference to the other pulley near the power steering pump, so it's of little help.

 

[gbu]

So I reckon I've narrowed it down. I replaced the pulley but I think it had been over tensioned in the past and bent the bracket it slides on, because the pulley wheel started overheating and rubbing against it. I don't think I helped to be honest. So I admitted defeat and took it to Magic Nissan in Melville, and they changed the whole lot out, and BAM!!!! Good as gold. The belt is looking pristine at last check, and no horrible noises from the pulley. That would explain the sudden start of shredding belts. Having a one off dodgy belt change bent the pulley traveller/bracket and the pulley wouldn't be running true over the surface of the belt.

 

[Old.Tony]

That's good news! I didn't know they were that easy to bend, I might have a good look at mine to see how that might happen. It would probably pay for me to take some Dri-lube along, and a spanner, because I've got a little belt chirping as she starts in the morning that I could do without.