Agreed hirnbeiss. That comment is strange. To do an oil change correctly you drain out ALL the old oil usually around 8.5 quarts and take off the old filter. Them put back in the oil plug and vube and attach the new oil filter. Then add approximately 8.5 quarts of new oil back in checking the dipstick as to where you are at. The start it and run it and check for leaks and shut it off and recheck the dipstick. It will go down by the amount it took to fill the oil filter, maybe about a half quart or so. I was not at all clear on how you are doing your oil changes. Hope this helps and apologies is this was too obvious.

 

Are you sure your mechanic is pouring oil and not four quarts of Vodka into yout engine?

 

An oil changer in Los Gatos overfilled my 8.5 qt engine because he kept waiting for the dash to tell him it was full. He assumed it had no dipstick and didn't look for it.

I changed the oil JIC on this used car after I bought it. Same oil changer didn't put the filter covering on right. I panicked because I thought the car was a loser because of the check oil message all the time. A German car mechanic solved it.

 

All the above stories are the reason why I do the oil changes and a lot of other work myself. For the rest I have a good MB-specialized 'indy' shop that I can totally trust with advanced work like the headgasket or a diff-overhaul. If you're not going to the dealer, people 'assuming things' will f*ck up your car! They simply see a more than 10 y/o car and think only 'so-so' is good enough and don't understand the passion and care we put in it. I just had my rims balanced today at a tyre center and I simply step onto the workfloor and watch what they're doing!

 

changed the carb and the fuel injector huh?

must be one hell of an engine you got under the hood.