280 te tappets
 

Friend has an 81 280te, which is a bit rattly at the top. he has done the tappets once, and he is a very good with engines in general, but not MB before. Is there a trick here to get them quiet, or could the rattle be something else? He said he set them to .1mm inlet, .2mm exhaust.
Power is good, idle is a bit rough, but it needs leads, cap, rotor , so we hope they will fix the roughness. Fuel consuption seems ok also.
TIA,
jp

Use a stethescope to locate the general area of the noise, then pull the valve cover and remove rocker arms in that area till you find ones with a significant wear line.

These engines weren't the quietest but the only way to tell if the rockers are worn is physical examination with them removed.

280 te tappets
 

Steve,
Do you mean that significant wear will make correct adjustment difficult or impossible to achiev? Can the arms be pulled without major dismantling?
Is there a manual on CD available anywhere for this model please?

jp

The rockers are surface hardened. They wear through first on a line across the face. This line eventually grows deeper and is like a bump in the road for the valve following the cam. The adjustment is still achievable, but the the bump causes the thing to sound as though the gapwere larger. Or something like that.

The rockers are easily removed with a special spring depressor. The valve is depressed and the lifter just lifts off (once the secondary spring is poped off.

928 te tappets
 

Steve,
So once off, they can be fixed (ground true, hardened again), or they have to be replaced?

thanks,
jp

If bad they are replaced. If done to spec the cam will also be replaced. On a M110 motor I would just replace the bad ones.

The M110 information is on the W123 CD. It is also in the Haynes "280 123 Series" manual.

Even with good rockers and a good adjustment, they are kind of noisy in my experience.