How would I know if I need a valve adjustment?
2002 955I 42,000 miles
Valves tighten as the wear occurs so the lift is reduced. First thing that is commented is harder starting. Also you may notice some diminished power.
Skoron
Would there be any unique sound difference?
At 42,000 miles you really do need to have the cam cover off and check properly. Guessing won't get you far. If the clearances are too tight the next thing is burnt valves which is much more expensive.....
:iagree....................how to do it............... it's in the sticky thread