2013 GLK250 engine blowby [OM651]

[@matejgr.8879]

I drive a 2016 E class with om651 250 CDI version with 80k KM on clock and its the same, also i work in a merc garage and i done this test on multiple om651 and everyone is the same... Same on almost new engines and same on engines with 600k Km on clock. Also my old E class 2009 with same engine with 310k km had this same thing.

[@jmdonasc]

Thats ok. I went nuts with the blowby on mine. Its been years now and still runs fine.

[@ferasara5130]

Totally normal, newer diesels has vacuum/venting pumps pressurizing the crank case apparently. Dont worry about it

[@vasilyru]

Would you provide a bit more details please? I'm having the similar blow-by and wonder if I need to check vacuum pump or something. Never saw that before. Thx!

[@eric199524]

My dad scared me when he told me check the oil cap and it was doing the same thing. I just bought a e250 with 90k miles. Dealer maintain. Mine runs great and no check engine light

[@falunbrick]

Block off the line from the vacuum pump. The vac pump vents into the crank case and causes weird "blow by". If you block off the outlet ports on the vacuum pump and it still does it you may have a issue. But tbh the crank case venting on some of these 4cylinder diesels isnt the greatest.

[@jfaz]

My 2014 E250 oil cap dances like crazy. 96k miles. Runs great pulls strong. Consensus seems to be this is normal??

[@bucketsbucket1593]

is PCV valve ok?

[@MBDieselFreak]

No idea, no signs of external leakage so I think the seals are still fine. Should check it though.