High pitched screeching

[Bigell]

Hi all. I've recently bought a 1.9l 1983 Aircooled and have been loving it. But the two times I've taken it for a relatively long haul since getting it a fortnight ago, she has intermittently omitted a high pitched screech at higher speeds (60+mph). It doesn't last long (and neither does the speed!) and sounds a bit like a belt at high tension, but I wouldn't know what.

As far as I do know, the cambelt has never been changed and since she's at >80k now I'm nervous it's about to go on me. Would these be the telltale signs? And should I be getting the belt changed before I go another mile?

Thanks in advance - I'm using the forum and not FB page here so this gets logged properly as I've found the forum massively useful so far!

Cheers.

[Wychall]

The cambelt will not make a screeching noise. The only noise you might get from a cambelt is a loud bang as the pistons and valves rearrange themselves.

The only possible in the cambelt arena is the tensioner may be disintegrating.

[RedGus]

If it is an Aircooled (presumably a 2.0L CU?) then there isn't a cambelt. The camshaft is gear-driven straight off the crank. The only belt that could squeal is the "fanbelt" for the alternator drive. They usually only squeal when they they are a bit loose, then you rev the engine a bit, typically when pulling away from a standstill. It is pretty easy to check the tension of the belt from the top of the engine. It should deflect about 15mm in the middle of the length between pulleys, when you push with your fingers.

James

[weimarbus]

For your peace of mind the Aircooled engine does not have a cambelt, only belt on the engine is to drive the alternator. this belt maybe slightly loose and need adjusting but that would usually squeal after starting the engine and there is maximun load on the alternator to recharge the battery after cranking the engine. you could try to load the alternator by turning all possible electrical load ie: headlights, heater blower on max,wipershazards and brake lights and see if you can reproduce the noise by reving the engine from tick over, if you can then it would be best to fit a new belt and adjust it as per manual

[weimarbus]

Redgus beat me to it I'm a very slow typist

[RedGus]

I think there's an echo in here!

At least we agreed on the possible diagnosis, though.

James

[sarran1955]

Hello,

So we've now established that 2 L CU aircooleds do not have a cam belt....

So where is the 'screeching' coming from....

Fan belts aside...

I think you may be looking at a dry bearing somewhere...

Alternator bearings..

You could try an oil spray with a tube..

Or maybe the distributor..

There is a felt pad under the rotor arm requiring a few drops of oil at each service....

Maybe thrashing it at 60+ mph is not the best...

Not until you get to know the van , engine, and Brakes a little better....

Aircooled bliss..

Cordialement,

[tobydog]

Disks squealing? Does touching the brakes stop the noise?

[Dazco]

I'd put my money on alternator bearing( if I had any money that is )

[CovKid]

So would I. Fan belts tend to squeal at low speeds. Once you get up to speed, the belt has invariably caught up, after its polished the pulley wheel a bit more that is.

[Bigell]

Many thanks to you all for the time and knowledge given to a newbie on here, who didn't even know an Aircooled had no cambelt. It'll be no surprise to hear I don;t know my way around an engine, so whilst I am relieved to hear it is not a cambelt issue (!), I am none the wiser where alternators and bearings are concerned. However, I will

check the tension of the belt from the top of the engine. It should deflect about 15mm in the middle of the length between pulleys, when you push with your fingers.

.

I have also calmed the mph down a bit. She runs well at 50-60mph.

One slight concern today on returning from a 100 mile steady drive in the heat. When I came to re-park her a few minutes after arrival, she kept stalling on tick-over and needed three or four restarts just to turn her around. And it wasn't just my clutch foot that was letting me down!

I have wondered whether such a strong smell of petrol is normal on ignition each day I come to use her. I have to open the windows just to breathe!

Many thanks Once again.

James[/quote]

[RedGus]

The alternator rear bearing is really easy to get to, once you have your engine lid off. While you're in there checking the drive belt, you may as well give it a drop off light oil. Just ask if you need more advice on where to put the oil, as per Sarran's suggestion.

As far as your other problem is concerned, with the difficult hot restarts and a smell of petrol, that sounds suspiciously like your auto-choke is sticking closed. While you have the engine cover off, you could check that too. The choke shouldn't really be coming on at all, unless you have set it before starting the engine, but your symptoms sound like an over-rich mixture for a warm start. A strong smell of petrol is never a good thing, though, and definitely not normal. There may well be a leak somewhere, which will need addressing urgently. See this Wiki section:

Petrol leaks and hose replacement

Good luck,

James