UK-POLOS.NET - THE VW Polo Forum

My fan belt (not sure what else to call it) is squeeking on cold start. This is inch wide belt on the left side as you look at the engine from the front of the car. Well, a VW engineer checked it out and said he couldn't hear anything from cold start - hmmm, maybe the technician was deaf then?

Anyway, to cure the problem, the VW dealer service manager suggested I spray WD40 or spray grease on the belt to stop any squeeks?!?!?

Is this correct, should I really do this? I would have thought this would stop the belt from gripping on the pulley wheels and cause non-charge of the battery etc?

Anyone else have a view on this

Sure, I have an idea. Go to someone else.

Squeaking means it's slipping, which could be wear or looseness. In both cases it's a normal fix (replace or adjust). No WD40.

Speedlaw wrote:Sure, I have an idea. Go to someone else.

Speedlaw wrote:Squeaking means it's slipping, which could be wear or looseness. In both cases it's a normal fix (replace or adjust). No WD40.

Actually I agree in part but not totally (sorry Alex )

- don't use spray grease that bit I agree with

But you can use wd40 in small amounts to dress the belt and it does quieten them down without any slipage

- multi v belts serpentine or otherwise are notorious for running slightly noisy when dry the rubber gets very dry - most are self tensioning so adjustment isn't possible - only repleacement when the belt is out of range on the self adjuster

Heres a trick - Used it for years

Spray some water down the front of the engine when running where the belt is - blip the throttle

- if the noise goes away it's a noisy belt and wd40 will quieten it down for quite a while

- If it doesn't and the belt slips and sqeals when you blip the throttle then it's probably reached the end of it's service life if self adjusting or needs adjusting if manual tension is set.

Hi morrisman

I had exactly the same nigglying squeaking belt and my friend who's a mechanic also recommended I use some WD40 on it. At first I thought the same thing that it would cause it to slip more. However I took his advice and just squirted a bit on the belt and hey presto no more squeak on cold mornings. It really does work the belts just dry.

Thanks

The VW dealer service said the belt was in good order, not cracked etc so did not recommend replacing it.

The belt does look dry. I'll try the WD40 trick first and get my belt lubed up.

I'm still surprised lubing a dry (friction) belt has no disadvantages.

Whatever the case, I'll best shut up.

My dad had a problem with a Mazda that we just couldn't stop it slipping. Without serious tension on the belt. We deterjmined that the pulleys had that shiney hard glaze that they get. You can remove them and rough them up a bit, but my solution was to use salt water. Normally you don't want salt water anywhere near the engine, but corrosion was what I really wanted here, Used a paintbrush and a some very salty water. left it overnight and in the morning the pulleys were redened. Started it up and it rubbed all the glaze off.

Worked silently ever since Peace at last.

I would not recommend WD40 on the belt. It should not be squeaking in the first place.

had the same prob bit wd40 on the belt and job done!!!! no squeak

Must be an epidemic of slipping belts, as mine has started doing this now too - how annoying! I'll dig out the WD40 after I've washed her later

Well, i gave my belt a good spray on the inside, and started her up today - no difference - still squeeks like a mouse in a tight thong. So, what to do now... Maybe need to look at this more in depth.

I believe the belts are faulty. Reason: My Volvo had to have a new belt as there was a faulty batch made by some Belgium parts company when the car was made. New belt from Volvo suppliers and no problem.

So, have VW obtained belts from the same / different third party suppliers (cos they're cheaper) and not noted that these are slipping?

As said previously, the belt should not be slipping anyway - rubber on metal pulley means grip usually. WD40 on belt + metal pulley means slip in theory. Now, my last car had a toothed belt so it would never slip. As for roughing up the wheels, this shouldn't be necessary either really as they are not designed to be pitted, abd if they were, then they would have been manufactured that way.

So, I reckon it's a design fault with the belts - they are not flexible enough and perhaps harden to much when cold.

Sticky coming on perhaps?

I do NOT recommend wd40 on the belt. As stated, it should not slip anyway, and if you put wd40 on it you just can't hear it slipping.

In the engine bay, on the pulleys, you get a shiny coating that is really hard, almost like a baked on ceramic coating. It is that which makes it slip, and no amount of tightening seems to cure it. Best bet is to take the pulleys of and clean them with wire brush. But as I said earlier, strategic rusting cured it for me. Making it corrode a bit roughed up the surface and took the glaze of the belt.

Not recommended on the MK5, but reversing the belt seems to stop it making a noise - can't figure out why for the life of me.

Ed - also WD40 may reduce the life of the belt causing it to snap prematurely. Most oils and the butane propellant will attack rubber.

bstardchild wrote:But you can use wd40 in small amounts to dress the belt and it does quieten them down without any slipage

- multi v belts serpentine or otherwise are notorious for running slightly noisy when dry the rubber gets very dry - most are self tensioning so adjustment isn't possible - only repleacement when the belt is out of range on the self adjuster

Heres a trick - Used it for years

Spray some water down the front of the engine when running where the belt is - blip the throttle

- if the noise goes away it's a noisy belt and wd40 will quieten it down for quite a while

- If it doesn't and the belt slips and sqeals when you blip the throttle then it's probably reached the end of it's service life if self adjusting or needs adjusting if manual tension is set.

Repeated above cos people aren't geting it

If it's squealing - it's slipping best I can describe is shriek shriek - WD40 won't help - well it'll make the noise less cos it will help it slip quieter

If it's noisy - best I can describe is shuffle/shuffle noise the WD40 is a perfectly acceptable way of conditioning the belt - ie softening the rubber that is dry and hard.

WD40 will not destroy the belt - it contains very little in the way of solvents

WD40 has been used as a belt dressing spray along with "Duck" oil for years

I use Anchor butter on mine, I find the unsalted butter works best...plus you can then fry an egg on it after it gets hot enough...yum yum!

Why not put Marmite on it, or better yet K-Y jelly.

If you belt squeeks a bit, if you want to change the sound you can move your steering wheel whilst stationary and play a tune. To make a different sound, turn the AC on. It makes a painful sound when you hit full lock. For added effect make sure you are low on power steering fluid.