dberger1

I just had the 24 hydraulic lifters replaced under warranty on my 2004 E500 at
5800 miles. They were very noisy. The new ones are quieter, but still noisy. It
is most noticeable under moderate acceleration, or uphill while under more throttle to maintain a constant speed. Has anyone had a similiar problem?
What was the fix?

DWP

I may be showing my mechanical ignorance, but does a SOHC engine like the one in the E500 even have lifters? Rocker arms, maybe, but lifters?

The noise you describe sounds like predetonation, a/k/a "knocking." Are you using 91-octane fuel?

dberger1

The work order calls them valve lifters. I believe they are on top of the valve
stem, under the cam lobes and the the rocker arms. They were "sticky" and
all were replaced. Now the symptoms are the same as before, just not as loud.
Premium is 92 octane here. The car has seen nothing else.

pfphipps

All recent USA Mercedes have hydraulic lifters. They may not actually “lift” but they are still called lifters even though they may push instead. They adjust the valve clearance automatically so valve adjustments are not necessary. They expand using oil to get essentially zero valve clearance. Sometimes the oil may leak out, especially when the engine is off, and the lifter will be noisy until it pumps up again which is usually a few seconds. Sounds like your problem is more than that.

RJC

1) Did you have the motor mounts changed?

2) All of the modual MB engines has been making since 98 have noisy valvetrains compared to the previous dohc 4 valve ones.

dberger1

No. I did not have the motor mounts replaced. I will ask at my next dealer visit.
Did not know about the history of noisier valve trains. Thanks much for the input.