I have a '81 300TD wagon with 275k.

I'm starting to go through a little oil. Nothing too serious but there are drips on the garage floor, driveway, and definitely on the bottom of the engine. I do not know the origin, to be exact.

The car does not smoke (excessively) and is perky. The only time I think it's a little doggy is trying to pass another vehicle when I'm already going 65 or 70.

You may have read my recent post regarding my mechanic's valve adjustment- without really digging in deep (I was on a time schedule) he was guessing that it was starting to leak at the main seal. He also noted oil in the air cleaner assembly, suggesting oil is getting by the valves (is that correct?).

He also said that it was exceedingly easy for him to turn the engine over manually and that this seemed to suggest poor compression.

Also, most of the valves were so tight they were barely moving at all.

Classic chicken v. egg: poor compression due to tight valves or some other process?

Again, he doesn't usually shoot from the hip but I was getting ready to go out of town so he suggested backing the valves out around 1/2 way to factory specs, to run it for a few 1000 miles and then bring it back in.

This is our only car. If it's going to need replacement, I want to know in advance so I can plan ahead.

What should be my next step?

adjust the valves to spec now. i would be really surprised if your mechanic has any credible evidence supporting doing otherwise. that little at a time process.

I've already had an avalanche of responses from my fellows on the Diesel forum stating my mechanic is a quack and trying to get extra $ out of me.

He said that he's seen dropped valves after going from screwed-down-tight to factory specs in one adjustment and i took him at his word.

i was heading out of town and didn't want to take a chance.

so IF i do have low compression in some or all cylinders is it due to the valves being too tight or something else?

adjust the valves to spec. if you have adequate compression, then end of story. if not, then something else. as some of the more senior types constantly lament, go with the easy/obvious items first.

You need to clean the engine so that you can find exactly where the oil leak is coming from.

I would be willing to bet that it is coming from the tube that goes from the air cleaner oil separator to the oil pan. This is very typical with the non turbo 617's. The engine is getting a little tired.

You should indeed clean and look for EXACTLY where the leak is coming from. If you determine that it is where I think then you should do a compression check.

It is most likely due to worn liners, pistons and/or rings.

Good luck,

I have a turbo.

Sorry, I didn't catch the fact that it is a wagon. The oil separator and return tube should still be an item for you to thoroughly inspect after you've washed everything down at the car wash.

Good luck,

wrap a paper towel around the tube. check in a day or two?