CLK 55AMG Burning Oil

[bdman]

Hi guys - quick question. Had my 03 CLK 55 for two years. Used to go through a litre to 1.5 litre of Mobil 1 0-40 every 2000miles. It's now down to 700 miles before I get a message asking to top up a litre. No blue smoke and no leaks as far as I can see. Any ideas what might be causing this? Thanks in advance

 

[kid-jensen]

If it's not on your driveway, or precariously filling up the undertray, it can only be going out of the exhaust..

Allways assuming the oil level measuring device (whatever it may be) is working properly.. A good old-fashioned dipstick can at least be relied upon.

A lot of oil can be burnt by a moderately clapped engine without smoke being obvious from looking in the mirror. Convince someone to drive behind you when you accelerate and watch your exhaust. Generally, smoke when accelerating tends to be worn rings...

Find a long steep hill and drive down it at say, 60. Lift-off the accelerator and coast as far as you can. when you've had 1/2 mile or so, put your foot down and watch in the mirror.

If you get loads of smoke, but only in this situation, chances are it's wear in the valve guide seals (and possibly valve guides).

All the above being said, a zero viscocity oil is pushing your luck with anything other than a new engine. Try something with a higher leading number, but make sure it has the Mercedes approval number.

 

[brucemillar]

^ this.

Also sit with the engine at idle for 15 minutes (when the engine is at running temp) then blip the throttle and look for oil smoke at the exhaust. That can show worn valve stem seals. The usual culprit on these is the rocker cover gaskets which can drop oil onto the exhaust manifolds, meaning it is never seen and never gets onto the drive way. It is worth pulling the engine cover and having a good clean up with a de-greaser, wait a week then run a clean cloth around there to see if you pick up any spillage.