I came across this earlier today:
"Hey Graham,
Just got my car back from the dealer, and there was a German Engineer Rep visiting the service bay that day who specialized in the n20 engine who explained to me that:
- The n20 engine when the cam lobes come to a rest vertically to the valves (very rare instance) they will rotate back slightly and cause slack in the chain
- Since the n20/n26 variants use a hydraulically actuated tensioner the chain will be taught or very tight only after the engine has warmed up to operating temperatures
Hopefully this is helpful"
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