I installed my new timing belt and related rollers and tensioner. I set the tensioner arrow just to the right hand side of the notch, and snugged the nut. After 2 hand cranks the tensioner arrow is back about 4-5mm to the LEFT side of the notch. When I hand crank to a tight spot in the rotation it gets tighter and the arrow moves back toward the right, settles around the left side of the notch. Is this ok? Is it supposed to relax back to the left hand like that, after a few rotations? I seem to remember it’s supposed to stay within the notch. I’m starting to wonder if it’s a bad tensioner.
Defective timing belt tensioner? Need advice
- Thread starter TDI-Guy
- Start date
iamatt
Veteran Member
Did timing belt yesterday and noticed similar thing where the arrow bounces back and forth. We locked it bias in to the right and went with that. Everything all good. Maybe 3-4 hour job but most of that is removing crap to get to everything . Make sure that tensioner tab is seated in that little square indentation too!
DSIre
Veteran Member
- Joined
- Jul 11, 2004
- Location
- Dumont NJ
- TDI
- 2004 Golf TDI (sold), 2011 A3 TDI, 2015 A3 TDI (Returned)
The older PD engines had a slightly oval lower sprocket to help balance the belt tension for the cam and injector effect of each compression stroke. I wonder if you are seeing the same.
Thanks for the responses guys. What I did find is that there is a small 10mm bolt on the backside of the block that holds the plastic cover in place (where the tang engages from the tensioner.) During removal of the lower timing cover I removed this bolt as well. The plastic cover shifts ever so slightly with this bolt removed. So I repositioned, reinstalled the bolt, reinstalled and set the tensioner. After rotating the assembly it rested within spec. Problem solved I guess. Over 1000 miles and all is well.
iamatt
Veteran Member
Just to clarify, You accidentally removed a bolt that holds on the backside of the TB cover? By backside I am referring to the side behind all of the rollers opposite of the other side which you remove to gain access to do the job? The back side with the waffle pattern up against the engine was then loose inadvertently?
Matt - that’s correct. As a result there was a minute amount of shift when I tightened the tensioner. Relaxing the tensioner completely, moving the waffled plastic piece back right against the lower piece, then reinstalling the bolt seemed to help that last little bit to keep the tensioner within specs.
iamatt
Veteran Member
I think that happened to me actually. I can't recall since was unbolting a bunch of things. Definitely will keep this in mind in the next 120K belt job I do. That tensioner was the only part that made me scratch my head but other than that nothing magical about the job.
Here is a picture of where my tensioner lined up. And my ghetto "metalnerd " lock tools
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