Hello,

New to me ML350 BT, 105k miles.

Purchased it from a dealer, when arrived I noticed oil level was at min, unsure of when oil was changed.

Drained oil, split filter open, looked fine. Foolishly didn't measure amount of oil drianed.

8 liters of MB 229.52 (was unable to get 229.51) and a genuine filter installed.

Checked level and was near max, shop temperature, engine off for 1 hour (?).

After oil change I drove the vehicle for 100-200 miles while waiting on parts.

When parts arrived, I've done a lot of preventive stuff, including the PCV valve.

Picture of when I removed y-pipe, originally:


Small amount of oil, normal?

Replaced PCV, belt, filters, idler pullies, etc.. to prepare for a long trip.

1000 miles later, checking oil 5 min after engine shut off resulted at min level on dipstick, waited a bit longer and level came up a few mm, below half maybe, hard time getting a good reading.

I decided to top off and set a reference point, I added another liter which placed me at right below max, with engine oil hot (90deg c).

500 miles later (today) I checked the level an hour after the engine has been off, oil temp is 32 deg c and I'm right below the half mark. I thought that while the oil expands when hot, checking an hour later will allow more to drip down to the pan from my last check, and I should have the same level as when I last checked.

Has anyone experienced something similar? Anyone found 9 liters to be more accurate? Any good advice on when to check level for most accurate readings? This oil does expand a lot when hot?

I'm reading horror stories about these engines drinking oil like there's no tomorrow, without external leaks or other obvious things (no mix with coolant, no smoke from exhaust).

I'm getting about 24-5 mpg, with full power and no obvious faults, but this is concerning to me.

Will appreciate any advice.

Congrats on your new addition.
In general, I find that it is best to take oil level measurements first thing in the morning after the engine has sat for several hours, preferably overnight. Repeat this process to guage your oil consumption amount. It is important to do this consistently for accuracy. The oil on this engine does not all return to the sump very quickly, making intermediate level checks difficult and inconsistent.

Regarding consumption, the OM642 does produce a lot of blowby, leading to the oil you see in the intake tube at the turbo. This higher than normal blowby has been noted for quite some time. Part of this is caused by the turbo intake and PCV design, where the turbo does draw quite a bit of oil thru suction on the PCV. Good that you changed the valve, staying on top of that will help improve things.

Ultimately I chose to add a PCV oil catch can and vent to atmosphere rather than back to the intake. Even with this modification, blowby is still over half a quart of oil per 5k miles. This is high as compared to my OM603 with twice the mileage yet consumes a third as much as the OM642. Every MB, Sprinter tech that I have discussed this with has said that was normal. I know my engine is in great operational condition, so I was surprised at this degree of blowby. I have not been able to determine why this is the norm for the OM642. If someone knows, please provide some insight

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Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)

Thanks, referring to the oil I saw at the turbo inlet, is that a normal amount?

I'd be happy with half a quart /5k miles, I had to add a liter over 2000 miles which is excessive in my eyes.

It may also be dropping again, but I will measure a few more times before determining that for sure.

Regarding whether what you saw at the turbo inlet as a normal amount, yes it is, on a stock setup. On many variations of this engine the leading cause of swirl valve motor failures is due precisely to the oil that you are seeing and a bad seal at that intake joint, allowing the oil to drip onto the swirl valve motor that sits right underneath of that junction, eventually frying the motor.

You can research the resistor mod should you want to disable the swirl valve motor or in response to it failing and throwing you into limp mode. The resistor can cure you of that problem temporarily or permanently depending on how you want to address it.

There is also a camshaft seal in the adapter that the PCV mounts to at the back of the engine that is also a known wear point, allowing more than normal oil to enter the PCV puck, and then engine. Most often, the PCV gets changed, but not the cam seal, so the PCV wont last as long nor be as effective with an old cam seal, better to replace both.

Even with that done, you will still get a good amount of blowby. IMO, it is best to eliminate the blowby altogether getting back into the engine, less to no oil in intake, and certainly no caustic gasses and moisture going back into the engine. A Provent catch can or something similar with external venting will help tremendously in that regard.

There are also fuel additives like FTC decarbonizer that have shown success in cleaning up carbon deposits on piston rings and reduce the amount of blowby generated, or do lots of Italian tune-ups to keep the carbon buildup at a minimum. City driving is the worst for these engines in that regard. They are much better running highway, but life is what it is, so several WOT runs regularly if you do mixed driving will help keep the carbon accumulation lower.

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Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)

Small amount of oil in pic is nothing to worry about. What you need to watch for is pluggage of the cat because of the oil. I had one in shop that was going thru oil like water thru your fingers but that one was at 250k+ milles. Seems it had been being serviced by MB and they had been using wrong spec oil. Owner settled with dealer and bought a Lexus. Never did get in to engine to ck rings but that is what I suspect was the issue.

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Jim

Thanks for the reply, do you recall what was the mistake with oil spec?

The vehicles calls for 229.51 originally, it's not possible to get this spec anymore from my understanding, which is why I had purchased the 229.52 which is supposed to be compatible.
Both are low ash, 5w30 full syn

I have an 06 Jeep grand Cherokee with the same om642 engine and Jeep recommend 5w40 for it and especially when vehicle is used for towing.

Mobile 1 5w40 ESP rated. I think it is available at Tractor Supply.

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Jim

Decided to take off intake y pipe after about 2500 miles since new PCV, same if not more amount of oil accumulated.




The next 2 pics are 600 miles apart, engine hot, 10 min timer since shutdown.








I think dipstick min to max is about a liter, meaning I'm losing 200-300ml every 600 miles.

Turbo? Rings? Valve guides? All would suck at 106k miles.

Change the cam seal as per this thread… changed this on my Jeep om462 and it stopped oil getting by instantly.
2011 GL350/OM642 oil consumption solved?

The oil filter element has the plastic tower it sits on , the small o ring at the base stops oil filter canister draining back to sump and if this is damaged it could be cause of varying oil level.

PCV valve is new, that seal is a part of the assembly as I understand.

Oil and filter were replaced 3xxx miles ago, O rings were changed but it's worth taking a look.

The camshaft seal, Part number 6420100131 is what the PCV mounts to. Very rarely does it get changed, but it allows a lot of oil to make it to the PCV and then the intake. The PCV "kit" includes the PCV puck and short hose to the intake. Did you replace that?

https://www.idparts.com/images/7658_ccv_cover_wkcrd.jpg

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Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)

I have that same combination as the OP (2014). I also have 3 other OM642 vehicles (2 ML and 2 Es) in our family - kids got my wife and my hand me down cars when they were in college.

All of the oil consumption points I have found have been mentioned by 87tdwagen in this thread. That seal at the back of the camshaft really needs to be changed out once you hit 100k. And don't overlook the dumb stuff, one of my son's cars was losing oil out the filler cap seal.

229.51 has been replaced by 229.52, perfectly acceptable to run 229.52 in this engine.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech