Actually your VR6 engine has 2 chains, a short one that goes from the
crank to a secondary shaft and then a longer one that goes from the
shaft to the two cams. Each chain does have an hydraulic tensioning
device that runs off engine oil. More or less it is a good system but
not as simple as the 5 cylinder engines cam belt.
It is also possible that one of the hydraulic cam followers has
failed and lets its valve make lots of noise. That would be simple to
fix.
Other then that its more serious internal engine parts. I hope you
have a warrenty left.
