This is for a 95 Passat VR6 with 110,000 miles.
I have a noise that sounds like the timing chain, but it is in the 1800 to 2000 RPM range and I can only hear it under load (while driving, not while rev-ing in neutral).
I need to change my valve cover gasket any way, so I figure I am 1/2 way to at least some of the timing chain parts. I was thinking about just replacing the upper tensioner bolt (to the newer style) and the upper guide rail.
With 110,000 miles it is probably time for a timing chain fix, especially with an old style upper chain setup, but dropping the tranny is a lot of work compared to just changing out the upper tensioner bolt and the upper guide rail. Can I change to a newer upper tensioner bolt and keep the old upper tensioner rail (I believe you can't change the rail without dropping the tranny)? It seems that the upper guide rail wears the most. Does this sound risky, asinine, or brilliant? Any ideas for the noise besides the timing chain?