Hallo,

I own a 420 SE (1989) with 310000 kms. Since quite some time now I can hear a ticking noise coming from the engine when I accelerate: it becomes louder when accelerating and it’s hardly audible as soon as I stop accelerating.
With the engine idling, I hear a ticking noise at both sides coming from beneath the black covers.
Uptill now I had the following parts replaced:
-2 camshafts
-16 lifters
-16 rockers (cam levers)
-timing chain
-distributor cap
-spark plug wires and boot
-gaskets inlet manifolds

What else should be replaced/repaired to get rid of this ticking noise??
Or is it just simply a question of a bad ignition timing that sets off the valves??

Please let me know something if you recognize this problem…..

Thanks in advance,
Rémy K.