Mercedes-Benz OM651 engine 200/220/250 troubleshooting for Turbo Boost, Mass Air Flow, EGR faults.

This is meant to the general guide to help troubleshoot some of the common issues that we see with the Mercedes 651 engine. Fault codes can often lead people replacing expensive Parts unnecessarily. Fault codes are always just a starting point and should be used as a clue for progressing your diagnosis. I hope my video helps.

[@dzieburs]

Have this engine in my C-class. So far have not sorted out power loss, rattling take off, suden turbolag, harsh deaccelerating in first /second gear. And car never gave any error codes. Seems like first torbo (of two) sometimes do not work or works not at full boost.

[@MrRagon11]

fan. First clean the DPF filter. In mine, I replaced half the engine and it turned out that the DPF filter was so clogged that the engine had no strength to drive. It showed turbo errors of the EGR valve air flaps. REGARDS

[@pFFiukas]

Thank's very helpful video. I've got p0Af92 , and p2263 , but the faults are intermitent. The rod of the turbo is like ticking , it's a bit loose. It sucks in a little bit , but not as fast as it should. Sometimes it's good for 1 week no eml , but sometimes few times a day it pops up. Smoke tested , haven't found any leaks. The p0af92 code indicating about the turbo.

[@abdulamiraalubaid3056]

thank you for the detailed video, can you show how to clean the EGR for the same mercedes model please?

[@simonread06]

Great video and covers the exact problem I’m having at the moment. I’ve changed the wastegate actuator on the front of the engine that controls the left hand most turbo, did I hear you say that there is another wastegate actuator that is exactly the same that controls the inner most turbo?

[@mercland6434]

@@simonread06 yes under the manifold so it’s easier to reach from below. It’s different to the above one though, it’s white and black

[@simonread06]

@@mercland6434 thank you, I’ll get searching for a part number and will go investigate that one too.

[@johnnyjones2899]

Vacuum pump giving rattle sound when i double press brakes… any idea how to check for leak?

[@Rohanmanek12614]

I’m the first person who liked this video if you are the second or third person to like please reply

[@janvilsgaard7156]

EGR is electric..

[@mercland6434]

Yes the EGR bypass valve is vacuum. I’m talking about loss off boost and poss places for vacuum loss in this video.

[@performancejunky3258]

@@mercland6434 Hi I have low boost fault on my Vito om651 twin turbo 2018. No obvious leaks after smoke test
Turbo seems fine no smoke
Just low power codes I’m getting are p0299 p2261 p00c400