Valve adjustment?
 

Hi Techs!

Does the M113.943 engine need to have it's valves adjusted? I've got at least one loose (noisy) valve and thought this engine was self adjusting.

BTW, what's the difference between the M113.942 and the M113.943 besides 5hp?

Thx, Ed

Both 113 engines have hydraulic lifters. I would try a good oil additive like BGs MOA and more frequent oil changes.

The 113.942 engine is used in the ML430. The 113.943 is used in the CLK430

Hi Steve,

You probably haven't seen my earlier posts, but I'm the oil change fanatic. The ML has had four oil changes in 7500mi.
I running Mobil-1 15-50 in it so do you still recommend an additive? Should I take it in for diagnosis by the dealer?

On the engine differences, I was wondering why the 943 made 5hp more, different cam etc.?

Thx, Ed

There have a few cars(trucks) with the M112/M113 engines that we have had to replace several lifters to rid the engine of noise. Your engine might need to have the valve cover removed so that the lifters can be checked.

Thanks Doctor!

I'll keep an eye/ear on it and if it looks like it's getting worse I'll take it in.

One other troubling thought, not to start a flamer, Steve got me thinking about my oil. This noisy valve just started making noise after my most recent oil change.

Fact to the matter is that I've been using Syntec in the ML since it was a baby. With the birth of the CLK I gave them both a fresh batch of Mobil-1. I did it based on this forums opinion of Mobil-1 and the fact my next oil change will be by the dealer and they will use Mobil-1.

It would be interesting to see if changing the oil back to Syntec quieted the motor down. The CLK's 943 is not making any noise but for all I know it's only ever had Mobil-1.