M103 engine and valve stem seals
 

I replaced my valve stem seals after I noticed an increase in oil consumption, smoke from the exhaust, spark plugs with traces of oil, and a considerable amount of oil in the intake after removing the throttle body. After a few hundred miles, I rechecked my work: oil consumption was down where as now I don't even need to top up between oil changes (7000 miles ±), spark plugs are clean and dry, and there is no smoke coming from the exhaust. However, I removed the throttle body and found some oil seepage, maybe less than 5 ml. Is this normal after a valve stem seal replacement or should the intake be completely dry?

Oil from the breather puddles under the t/b. Pretty much normal to always have a bit there.

Sounds normal to me. It certainly doesn't seem to warrant pulling the head. When the time comes, however, these engines respond well to head work. The bottoms seem to last forever making a valve job worthwhile when the time comes.

Hope this helps.

Agreed, I did a valve job around 270k on my 300SEL and the bores were still full of crosshatching. Dry compression test revealed between 160-170psi on all six after the valve job.

Total cost was about $650 only, including machine work with all 12 new valve springs and all 12 guides replaced.

Car just spent 70 miles going 75mph yesterday on the way to dinner... no issues. :)

Great price
 

Dang that's cheap for a head gasket replacement and valve job. That's at least $900-$1,200 from an indy MBZ shop in the Sacramento, CA area.

I did the work work myself, there is the differential in price.

Machine shop was about $325 labor only.