Before I begin regular usage of the 560SEL there is further maintenance required. Per a receipt I have, a new timing chain and tensioner was fitted around 20,000km ago. This is obviously a good thing, but it was a shame that while this was done, the M117 timing chain guides were not replaced.
The guides (and ideally the sprockets) should always be replaced at the same time as the chain. It is actually the guides that are the cause of most of the problems in the M116 and M117 engines. A stretched chain just exacerbates the problem.
In the picture […]
