I understand (e.g. from this site) that timing chains can last a long
time on M103's. However, since I am not the original owner of my car
(1991 W126 300SE), and to be on the safe side, I decided to have the
timing chain changed at its current 127,500 miles.
I had also understood that it was advisable to change some timing chain
guides/rails (and maybe sprockets, etc.) in the process, so I was
surprised when only the chain and tensioner were replaced. When I
inquired I was told that changing guides/rails is both unneeded and a
"big job" on the M103's, and that it's in fact only needed on the V8's
(i.e. M116's & M117's).
Changing subjects, my exterior temperature gauge currently either is
blank or displays temperatures in the 130's. I was told that the whole
dashboard must come out to look into the problem.
Opinions on any of the two subjects above?
1991 W126 300SE