Squeaking Aux belt

[Racemag]

The Aux belt on my 1996 2.5 petrol T4 started squeaking slightly on start-up. This became a full piglet-trapped by the foot squeal a short time later. I thought mis-alignment, then the faulty AC ... so I got under the car and tried to take the Aux belt off, but had a little trouble. The arm-style aux belt tensioner snapped back into place and on startup, bingo no squeal at all.
So the tensioner seems to be the problem ... do people lubricate them or replace them?

[Sunny43.5]

Yes I would its fairly easy to remove the tensioner and lube it up and refit it . Use a suitable tool to lever the tensioner back and remove the belt then there is no tension on the lever so removal is safer and easier .

[jets]

Yes I would its fairly easy to remove the tensioner and lube it up and refit it .

Depends on what you call fairly easy. Just looked at the Bentley manual & the design looks the same as the TDI. Removal involves disconnecting engine mounts, lowering as far as you can & pushing engine forward. I think it would only be easy with engine removed from van.
I agree with Sunny that removal & lube would be the first thing to do. It doesn't look as if the tension spring is broken if it snapped back.

[Racemag]

that sounds very ordinary, i.e. lots of work. The tensioner has a long steel arm section ... the unfortunate thing is my copy of elsawin no longer works, so I have no diagram on how it attaches. has anyone see one online?

[Racemag]

Took out aux belt arm from the spring unit to find it dry of lubricant. Cleaned it up and greased it and put it back in. Reassembled it and found the squeaking gone, though I am suspicious that it is not a permanent fix as the squeaking has gone before.
The belt is a gates 1600 I think ... is this the correct belt?

[Sunny43.5]

Maybe the actual spinning part might need replacing it has a bearing inside from memory .

[jets]

Maybe the actual spinning part might need replacing it has a bearing inside from memory .

If it is the bearing in the idler, it can sometimes be saved by removing the seal, cleaning & refilling with grease. This picture is from our Polo for the timing belt, & while it was not noisy it was dry & I hadn't bought one ahead of time. It's been going now for around four years.

[Racemag]

bearing noise is different. Pulleys are worn and belt is new...wonder if they are a good match.
Anyway I was at phillip island race track today, but on startup this am the sqeal was back and I hated the dame truck! drove the 150km with the squeal gradually getting louder. Squeal was louder at idle and almost disappeared at 300rpm...mind you other noise could have masked it.
So at the track I got advise to spray the suspect pulley with WD40. Supposedly this will help 'bed in' the belt. I was skeptical but the next choice was to replace the damn belt, so I tried it anyway. Short squirt of oil and noise disappeared. Bigger squirt and all seemed good. 10km downt he road and LOTS of noise and increasing noise on rev/acceleration indicating increased belt slip and I had 150km to home. Half way home noise abated and 3/4 way hone no noise. Will check it in the morning to see what it is like.

[Sunny43.5]

Oil on rubber belts is not a good combo especially long term anyway , it can break down the strength of the rubber .Have you removed the belt and checked for another pulley that might be starting to seize up .

[Racemag]

I checked every pulley when I had the belt off and all spun very freely. There was a little bearing noise with the AC pulley, but it span well and for a number of seconds with no apparent drag.
Started this am with no noise. The pulleys will be worn, after all the truck has done 400,000km, so the match to the belt will not be great.

[Sunny43.5]

Yes I think the inner surface of the belt may get sort of polished to the extent that it will not have much surface tension meaning it will slip very easily or not have good contact with the pulleys resulting in the noise new belt would be the best option .

[Racemag]

yes, will be changed when I can find a replacement.