I’m no stranger to the clickity-clackity sounds the M112/113 engines make at idle but today for some odd reason it’s BOTHERING me. Of the Crossfires I’ve owned, only two had it to the point where it truly annoyed me. Let’s walk through the possible issues that plague some of these engines, according to the interwebs…

a. Noisy lifter/frozen lifter (highly likely)
b. Stuck or partially stuck rocker arm (likely)
c. Oil pump chain slack, causing the oil pump chain to slap the timing cover (more of a V8 issue)
d. Partially clogged oil passage at the rear of the cylinder head (I’ve read multiple accounts of this)
e. Low oil pressure at idle
f. Other crap, it’s a Mercedes Benz engine after all

The oldest Crossfires roaming the earth are over 20 years old and these engines have been on the roads since 1997, making the oldest living versions approaching the 30 year mark. Numerous articles online document the clacking and tapping noises at idle, but it’s hard to find someone post something useful with a clear resolution or solution to the issue.

I would be okay be with the sentiment being “it’ll run like that forever so just deal with it”, but there’s gotta be more to the story right?

my question is, have any of you spent time trying to diagnose the noise and come with a solution?