Keeps breaking auxilliary belts

[expat2000]

Hi all

Need some advice. Two weeks ago my auxiliary belt snapped. No damage so replaced it and went on my merry way. The one that snapped was only 8 months old, and was replaced when i replaced the tensioner, so was a bit annoyed but didn't think to much of it.

Yesterday it snapped again. Again luckily no damage but I am sure there is an underlying fault that needs to be fixed.

Engine is the 1.9 TDI AFN car has 279,000km on it.

I can't see any obvious problems, all the pulleys seem free to move and can't see any out of true.

There is a bit of looseness in the tensioner that I put on in April but not sure if it is enough to cause the belt to snap although the tensioner does appear to be rubbing on the cam belt cover.

Attached are a couple of videos, the first one shows the looseness in the tensioner pulley at around 30 seconds, the second video shows the pulley rubbing on the cam cover.

http://s254.photobucket.com/user/e...udi/VID_20150101_142236_zpsyqs1j8fo.mp4.html

http://s254.photobucket.com/user/e...udi/VID_20150101_143545_zpszutnx0o6.mp4.html

Thanks

 

[spartacus 68]

Bearing collapse? Difficult to tell with no tension on it. You really want to get access to the engine to look at it properly. Looks like it's bumper off and put it into service position.

 

[expat2000]

Bumper is off and front is in service position already for the video. Can't even reach the tensioner pulley without doing that.

 

[aragorn]

almost certainly the tensioner, had this a few times on 1.8T's

 

[jbh]

as Kev says its the tensioner ive seen it on a few AFN engines. when the belt is on youll see the tensioner will be running off. ive got a mates passat to fix with the same problem

 

[expat2000]

Hi guys,

Thanks for all your help so far. Now I have to decide on whether to get another pattern tensioner or splash out on a genuine one. Will call Audi tomorrow for a quote/laugh/heart attack. Pattern ones are £35 plus a but of postage to Norway, will update you once I get a price from Audi.

 

[expat2000]

Just phoned Audi in Oslo, they have one available this afternoon. Unfortunately the cost is 1939kr which is £165 or $260 or €215 depending on you favourite currency so that's not going into happen today.

Might look into used ones as a used genuine one may be better than a new pattern one.

 

[MaverickTDi]

That does seem rather steep even buy OEM standards! I'd be cautious if you go down the road of a 2nd hand OEM belt as you could experience similar issues to what you've already had. IMO always buy belts brand new. Perhaps try a different manufacturer of belt?

 

[Oranoco]

My old tensioner used to split the aux belt in 2 in the middle

 

[expat2000]

I think I have found the problem!

Looks like the pulley has cracked and the screws have snapped and one of them has jammed against the mount causing the fan pulley to seize in place so snapping the belt.

Looking for another fan and pulley now.

 

[MaverickTDi]

That'll do it

 

[expat2000]

So just spent some time separating the cracked pulley from the viscous coupling. Had to drill out two bolts which had snapped but got that done without too much drama. Then found that the pulley was actually welded to the viscous coupling. I now suspect that this pulley has given a problem before and one of the previous owners has decided that rather than replace a cheap part they would weld it up and store some problems for the future....welds got chiseled off so now the pulley and coupling are apart. Only part that needs replacing is the pulley as the coupling is fine.

 

[MaverickTDi]

Jesus, proper bodge job! Glad you sorted the problem though

 

[aragorn]

check the bearing in the aluminium casting is free to turn!

 

[expat2000]

Bearing seems fine in the casting, moves freely and no sideways movement.

 

[spartacus 68]

Thanks for posting update... although it looks like a chuckle brother job!

 

[expat2000]

Further update:-

So dropped into the Audi spares dept this morning as its not too much out of the way on my daily commute (by bus). Nice that it opens at 7am.
Thought it was worth checking the price of a new pulley as most of the breakers here are listing the whole fan/viscous coupling/pulley as a unit and wanting 500 NoK (about £45) for the whole assembly.
Pleasantly surprised/shocked that a new pulley on its own is 260 NoK (about £23). I realise that this is probably double the UK price but its local and genuine Audi part and they can get it for this afternoon so collecting on my way home. Sorted!
Will pick up a new belt tomorrow and have it all back together before the current warm snap ends, currently hovering around 0 deg C so no problem working outside.
Thanks for all your help and encouragement.
Stuart

 

[expat2000]

Final update:

Weather and family commitments meant it was Saturday morning before I had time to put it all back together. It was snowing but not heavily and temperature was only a few below zero so not too bad to be working outside
Re-assembled pulley onto viscous coupling and fan, whole fan assembly into car and belt on. Getting proficient at fitting this belt now (4th time since April). Start car and all is well. Everything seems to be working as it should. Hopefully I wont need to do anymore to the car for a while. I plan to replace both outer CV joints in the spring as rubber boots have split on both but it doesn't seem like too bad a job.

As a side note, it is easier with the front in service position but, if you are doing just the belt, it is simple to do without service position by removing the boost pipe where it fixes to the intercooler and you can feed the belt in from the side. That's for the AFN engine though, might not be for petrol engines.

Cheers

Stuart