Does the M117.982 engine have Solid Valve adjusters or Hydraulic lifter??

[scia63]

Does the 1972 M117.982 450SL engine use manual valve adjusters or are hydraulic lifters used at the rock arm pivot point?
Recently developed a mild ticking at cylinder #2 on the right engine bank of my 1972 450SL. The ticking gets progressively quite as engine warms up.


Ticking goes away when injector wire is disconnected.

Engine health very good with steady19 inches Hg of vacuum.
Recently replaced all spark plugs.

Recent oil change 10/30 w for easy winter starting in NE.
Replaced #2 injector because the ticking sound appeared to come from the injector.


Should I adjust valve clearance or should I be looking to replace a hydraulic lifter (aka "Hydraulic valve clearance compensating element") to eliminate the ticking.

[Frank Reiner]

The cam follower pedestals are manually adjusted, aka "solid".

[scia63]

Hi Frank, Thanks for your response. Just what I summarized but a little confused.

Just to confirm the ticking should be gone when either Intake or Exhaust valve is adjusted cold to proper clearance, and maybe I'll have to replace the thrust washer.

I would appreciate any further insight or links you would like to share on this topic ?

Seems adjusting valves is a common and routine service but the M117 manual is obtuse on this and other topics.

Thanks again,
Frank Sciannameo

[Frank Reiner]

With the cam covers removed, hold a mirror behind the back of each camshaft. Code nos. are stamped into the back end of the shafts; you should see either 54/55 (left/right), or 56/57. Those are the nos. for mechanical adjustment.
If you see 00/01 codes, then the cams, and presumably the heads, are from an engine of '76-80 vintage.

[scia63]

Hi Frank, Thank you for the valuable education. much appreciated.

One more clarification on terminology:
The rocker arm pivot point thingy in the early M117 engine is not a lifter because there is no lifting going on, but rather a " Valve Adjusting Screw" as per the wording in the M117 Manual.........correct?

The Mercedes EPC labels for the rocker arm pivot pedestal is "Set Screw and Ball Pin".

Thanks again from this Frank.