so my tensioner has 380,000km on it (new timing belt at 350,000km, those things last a long time) and I have bought a new tensioner after being advised by several people to replace it ($30, not much really). My question is about the amount of tension to put on the belt. With my old diesel rabbit I just tightened the tensioner until I could almost turn the belt 90 degrees in the middle with thumb and index finger. Is that the same thing you do with the 1.6 TD engine in the 1988 Jetta? Anything else I should know about replacing the tensioner? I assume I just clamp the belt in a few places to the sprockets so it won't move, remove and install new tensioner, tension it and that is it? Should I check the pump timing when I'm finished?
Since you have it apart to replace the tensioner it would be good time to check the seal and maybe replace the belt. If you have done it before and have the tools it should be a easy job and will insure you trouble free timing problems. If you have never done it can be a hard first time and the tools are not cheap. In any case I would not clamp the belt to the pulleys, but that is just me
somebody already replaced the belt 10,000 km ago (when they rebuilt the bottom end of the engine) so all below the head gasket is new including all seals (rear main, etc). Everything above the head gasket is original. So all I need to do is replace the tensioner. Kind of stupid really, but I didn't do the work. My valve stem seals also leak oil because for some strange reason, he didn't rebuilt the head. I don't want to have to re-set the timing if I can avoid it. I have all the tools to do it though.
I just got the bentley manual for the Jetta. The procedure for resetting the timing is actually really easy and I have all the tools. I'll probably just do that just to make sure it is right after I replace the tensioner.