norcalcasey

Hi All. I have a 2006 C55 with 165k. I got it from a friend who doesn't know anything about cars but he only had it for 8 months. I've driven it about 1800 miles at this point, and the car has asked for a quart of oil around three times. I have seen blue smoke on cold start once or twice, but only if I had previously just moved the car in my driveway. It does have an oil leak as well, but rarely drips onto the driveway, so it probably isn't accounting for all of the oil consumption. When I got the car I changed the oil with 5w40 Shell Rotella T6. Anything you guys see that you would tackle first?

Change the valve cover gaskets and breathers? I rear somewhere that there was a TSB for oil consumption and breathers.
Do a dye test to find the leak?
Change to a different oil?

Thanks in advance! - Casey

feets

With 165,000 miles I'd say you've got a high mileage engine that is going to burn some oil.

My 2006 C55 will go through nearly a quart per 1k miles and I'm at 97k miles.

If you want to stop the consumption you're going to need some rings, valve guides, and likely fresh cylinder walls.

Nokiemon

These motors are built with a bit more "loose" tolerances than others for longevity and reliability. It is not uncommon (As noted by Mercedes) for them to drink a quart or so, give or take, every few thousand miles.

My current C55 does not drink a drop, but my previous one with the M113 NA motor liked to be topped off with extra oil every 2-3k miles, so it does vary.

If you are experiencing consumption at a rate you are not comfortable with, I would have a good MB tech look at it to make sure there are not other issues as mentioned above, valve guides, rings, etc.

You can use the search engine here to pull up a number of threads on this topic as resource info, for one suggestion.