M103 valve guide wear?
 

Does anyone know a method of checking the M103 for valve guide wear?

I can remember years ago a method for setting up a dial indicator and measuring axial play (non MB engine).

I plan on at least replacing the seals, but would like to get an idea of the guide wear without pulling the head.

Any input?

TIA,
Joe

Yes you can drop the valve a bit (after removing the spring) and wiggle it with a dial indicator set to record lateral movement. Depending on OE wear limit specs the measurement should probably not exceed .006-.010". Keep in mind that this test will typically show more than actual clearance since you are tilting the valve stem relative to the guide.

A new valve guide should be very snug (actual clearance of .001 to .0015"). From a practical stand point you can just wiggle them and tell if they are excessively worn. If they have more than a barely perceptable amount of play, they are worn.

Duke