Hello, i have ML350 Bluetec, w166, 2013. Engine om642.826. The car has 120000km on clock. The car uses about 1 liter engine oil, for every 4000km. (1 quart for every 2500 mile) Is this normal?? The car is fine, no problems or codes. Just wondering about this oil consumption. No external leak. Oilcooler seals are new this year, engine breather replaced at same time. No blue smoke, no smell, no dpf problems.. But the oil consumption is about 1 liter for every 4000km (1 quart for every 2500 mile)

Is it OK??
Using Mobil 1 ESP 5-30.

Regards

 

Off hand that does seem high.

72,000 miles in 8 years, if you've owned since new... Weekend trips only? Or perhaps very short commute?
If no external/visible leaks the most likely culprit is the crankcase breather/PCV valve on the rear right valve cover (it's Waay back).
It has a sprung diaphragm which can let go and allow too much oil to pass into the intake system.

But also consider, the larger percentage of time the motor is running while not fully warmed up, the more blow-by and crankcase venting of oil will occur.
That's why I mused about the mileage - if it's lightly used It could be just because of a short heat cycle.

I think I added 1 liter over the last service interval for mine, it has 160k miles on it now. And my commute is only 13 miles.
I'd say is worth at least checking the PCV valve.

Another thing I've not seen mentioned on MB World is the possibility of vacuum leaks.
Although the vacuum system only consists of the pump, the line to the brake booster, and the booster itself - if it Is leaking any air coming in gets pumped into the crankcase and must then be vented through the PCV.
This scenario is not uncommon with other diesel makes.

 

That not normal at all ! I will definitely check for leak. My car has 230 000 km and did not burn any oil in between oil change.

 

The PVC engine breater is replaced for 20000km ago, did it in the same time as i replaced the oilcooler seals. I just talk to the dealer.. They say cars is different.. Some cars uses a bit oil, and someone does not. However, the dealer say the om642 is allowed to use maximum 0,8 liter, pr 1000km.. Thats horrible much. And i was not happy with the answare from the dealer.

 

If the oil cooler seals were re-installed improperly they can cause oil consumption and other problems. You might ask about that.
Is this a new increase in oil consumption since the oil cooler? Include that in your "ask."

 

While it may be on the higher side of average, a liter per 4000 km is not excessive and would certainly be considered to fall within the normal range. Has this always been the case or are you now (after the repairs) using more than before?