I have a 2004 c240 wagon. Recently it started consuming massive amounts of oil, but not consistently. Over longer drives, 50 miles or more, oil appears to be collecting in the intake manifold. if you floor it, or go up a steep incline, the oil gets sucked up into the cylinders and causes stuttering, misfires and error codes. I have bypassed the PCV by putting a separate breather and temporarily sealed off the vacuum from crankcase ventilator. that seemed to slow the oil sucking, but when I bypassed the vacuum off of brake booster/valve cover, the oil consumption was instant and massive. Unsure what the issue is. I can not see where there is any oil journals that would effect the intake. I would like to find where the oil is coming from without tearing the top of the engine apart. Anyone have this issue? I have ordered a new crankcase ventilation tubing and an new PCV valve, but like I have said, I have bypassed all of this and the oil consumption still continues. Its not rings or valves, the oil burning is very, very sporadic and only occurs over long drives, and it is very sudden, like needing a smoke screen and hitting a button on the dash. sounds funny, but its really not because you cant see anything behind the car and people behind you cant see in front of them when it happens.

 

Resurrecting this old thread. Have you found a cure for the issue on your C240 Wagon. My '02 C240 has the same issue. She is sitting on 224000km ( Around 140k Miles) on the odo. It will smoke up the whole highway then it will be gone and most of the times it will follow with a Orange low oil level warning indicating 1 to 1.5 litres of oil short. With all this she will still be running fine, no codes or anything. I have replaced valve stem seals, engine was flushed recently during service. Checked compression and all 6 cyl are approx the same values so I recon the rings are still ok. Checked crank vent pipes all in order I bypassed the PCV sytem as well with a catch can but the car is still doing the same. Any ideas?