Squealing 300tdi

"McBad" wrote in news: snipped-for-privacy@brightview.co.uk:

This one is a hardy perennial. Do a Google -- then take your choice. Suggested solutions (if a dash of water removes the squeal) range from roughing up the tensioner wheel with a bit of emery paper to replacing the engine.

Have fun!

Derry (Who has developed occupational deafness)

Give the belt a quick squirt of WD40 or similar, if the squeal stops it's the belt. If it doesn't then it's something being turned by the belt. I've seen a belt tensioner bearing collapse completely after the squealing has been ignored for a few months!

Andy Fox

Pardon the intrusion, but I would use a drop of water; does same job and does not rot the belt ( WD40 is a solvent)

I've never had any problems with WD40 (well, Castrol DWF actually), only a short blast and if it stops the noise it soon comes back as the spray dries off.

It's not a fix, just a means of locaating the fault.

If I've refilled a motor with water and spilt any on the belts it normally makes them squeal until they've dried out - never tried a drop though. The other problem with WD40 and similar is a fire risk if you squirt the hot exhaust, so water is probably a better idea!

Andy

Very Very common problem with the 300TDi

The tensioner part no ERR4708 has a very small plastic bush/collar between the two halves that over time begins to wear uneavenly due to the pressure exerted by the belt. This allows the two halves to no longer run parrallel allowing the belt to slightly track out. Once this begins to happen the belt and pully begin to act like a stylus and record cuasing the squeal. This is why short term fixes like water, wd40, changing belt direction or replacing the belt only last for a short period.

Very badly worn tensioners will allow the plastic collar/bush to split and stick out like fine hairs at the top side of the tensioner.

Swap it, It will cure the problem.

Alternativly by ear muffs.........

Brian Tonks Tonks4x4

On or around Wed, 31 Aug 2005 07:12:01 GMT, "Brian Tonks" enlightened us thusly:

however, ours squeaks despite a new tensioner. Tensioner bearings can also fail, as happened to ours. The squeak on this one is provisionally defined as being down to a non-genuine belt. At some point, we'll try a genuine belt on it.

see above...:-/

Thanks all.

I've just been outside with the watering can, and dribbling it onto the running belt brought instant silence. Wonderful. However, a couple of minutes later when the water had dried off the noise returned.

I'm going to cross my fingers on this one and hope it will last another couple of thousand miles; off up to Scotland on Friday and I haven't got time to do much about it before then. Will have a look at it when we're back - pretty sure I saw an article in LROI about how to change that tensioner about a year ago and it didn't look like too bad a job... I'll go through my back issues...

thanks again,

M.

The squeel on mine was from the air con belt being pulled over the idler which had collapsed its bearings and siezed. New idler and belt cured this one.

Peter.

It's easy to change, just one bolt and it comes off. Just make sure the tension is off it beforehand, it has one mean spring.

Peter.

so Pete S was, like...

Related question:

I recently did the cambelt and changed the serp belt as a precaution (it wasn't squeaking, more a mechanical-sounding chatter from the front of the engine). While it was off I noticed the tensioner was running out of parallel as Brian describes above, so I ordered a new one of those as well. The noise has gone, but the new belt (

"Pete S" wrote in news:4315ed9f snipped-for-privacy@mk-nntp-2.news.uk.tiscali.com:

That sounds logical. The most acceptable explanation (to me) for the squeal is that it is caused by vibration. Like that produced by the bow across the strings of the violin. This suggestion was given to me by a technician working for a large belt manufacturer who likened it to a finger being drawn down a damp window pane.

If belt and tensioner are slightly out of alignment due to wear in that plastic bush/collar you mention, the belt could be sliding sideways (to a very small degree) across the tensioner as it rotates as it is not ribbed like the other pulleys to keep it in line. Have I got that right?

But does that mean the tensioner is about to fail? I would have thought the bearing would still be good for many thousands of miles as the squeal does not originate from the bearing but from the infinitesimal sideways movement of belt across the surface of the tensioner. Indeed, the squeal seems to be a characteristic of nearly all 300Tdi's I have listened to and most owners just ignore it (as I have done on mine for the last 12,000 miles) without any problems.

So, where exactly does the squeak originate from (on most 300's)? Belt on tensioner or from the tensioner bearing itself? My money is on the first in which case there is little danger of the tensioner failing.

Derry

Try a can of "belt dressing" - works on the steering pump belt on my 101.

Steve

Seeing pouring water onto the belt caused my squeal to instantly vanish my money is with yours, on the belt / tensioner interface rather than on the tensioner bearing.

Cheers,

M.

On or around 31 Aug 2005 22:22:17 GMT, Derry Argue enlightened us thusly:

we had a tensioner bearing fail, which makes a different noise. Meanwhile, ours didn't squeak until the belt was replaced with a non-genuine one. Yet to try a genuine belt to see if that makes it quieter.

"Nessun maggior dolore che ricordarsi del tempo felice nella miseria."

There is no greater sorrow than to recall happy times in the midst of misery.

Jeez Austin, that's depressing!

DaveP

finger (on

spare, which

Yes, I had a belt stripping fibres from the radiator edge which I also chose to ignore, after around eight hundred miles some sections of the top layer of fabric detached shortly followed by the first/outer groove of the belt which whipped around the engine bay shredding the soundproofing and puncturing an oil cooler feed pipe but did stop it squeaking for the next 50 miles until it finished emptying the sump ! This was a new belt (Dayco ?) lasted about 3 weeks, looks like the tensioner bearing had collapsed at the radiator end. Fixed with new tensioner, new belt but same old squeak.

ChrisG Def 110 300tdi '96

so ChrisG was, like...

Beamends supplied the belt, and Richard is sending me another one as he reckons the Britpart one is faulty - he's never heard of it happening before. We shall see...

Thanks Richard, BTW.

Another instance of belts tracking out. I came accross a gentleman broke down at the end of a dual carriage way near Rainworth. I stopped to see if I could lend a hand to find that the belt had tracked out and gone behind his water pump pulley.

Results were that it ripped the water pump pulley and spindle out of the front of the water pump.

I have also seen similar situations but with the power steering pump.

Brian Tonks