This is becoming a problem with these VAG diesels. Here is a contribution I made on 5/12 (there are no post numbers on this site). Scroll back about 4 pages in "Technical" and you will see it under "VW Passat - Cambelt". Best of luck.

I have changed a number of cambelts on these engines - without any problems - but I do not observe VAG's recommendations for tightening the nut on this tensioner stud. It is my belief that the stipulated 20Nm + 45 deg is excessive and will lead to a weakening of the stud through plastic deformation. The stud is unfavourably dimensioned at M10 into the cylinder head, necked down stepwise to M8 in the tensioner, which is secured with a 15AF flanged M8 nut.

I believe this problem emerged when VAG changed to the otherwise exemplary Litens tensioner which requires a smaller fixing stud to accomodate the self-adjust eccentrics. The earlier tensioners used an unstepped M10 stud - VAG presumably fitted a stepped stud in order to avoid making changes to the head.

It is also interesting to note that Continenetal include a replacement stud in their kit, wheras VAG do not. Both kits include new nuts.

My own approach with this engine is to re-use the stud provided it is undamaged and provided there is no evidence of non-elastic deformation of the stud whilst the nut is being tightened. I then tighten the nut to 20Nm + 20 deg when the tensioner is correctly set.

These are my own findings and do not constitute a recommendation. I have found other instances of stipulated tightening torques on VAG vehicles which, in my view are inappropriate and will lead to failure on re-use. I believe this arises from VAG's reluctance to use locking washers of any type on any fixing, and to rely on fastener stretch to give preload. This is not good for parts which require repeated disassembly without renewal.

I wish you the best of luck in resolving this problem with VAG - you will need it. I have found their unwillingness to admit to the most blatant design errors to border on the unbelievable.

659.

Edited by 659FBE on 13/12/2012 at 15:49

sorry it has taken me some time to reply mine was a 57 passat 2.0 tdi same problem

my Vw has been stripped in vw garage now for over a month as i am fighting this the belt has not go in reasionable time after beening fitted the stud should last longer than the belt ? whats the point in having the cambelt changed !

i am fighting it out with garage. VW customer care are no good.

the car will need a new head at the cost of 3400 + 500 for the new belt which i payed little while befor !

ps VW cambelt kit does not inclued in the kit, although it should be checked and last the time changed as it is ment to last the life of the car if not more !