Snibble:

The amount of oil you are using isn't extraordinary on an M103 at 180,000+ miles. At least you have a later engine with the harder valve guides, so at best you are looking at valve guide seals. Worst case, of course, it a valve job. Pretty typical at that milage.

However, first replace the oil filler cap (or just hte gasket). They start to leak about this age, and it's hard to tell since they will only leak significant amounts at highway speeds, where the oil will drip clean off the engine before you slow down. My TE has only used a half quart of so since I replaced my filler cap in July last year, instead of the quart every three months or so (my mother drives it, usually not on the highway).

As for the milage, it's also time to check the mixture and O2 sensor -- if the senor is slow responding, you will run rich and burn more fuel.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!