GoodByeHonda

With some time on my hands, I read in one of Tom Stephen's articles of an issue affecting OM642 engines that have been mostly serviced by the dealer. I.e. Mobil 1 engine oil and long oil change intervals.
Well, that's my motor for its first 100k miles. And the issue that he raised is cylinder wall glazing. So, how do you eliminate cylinder wall glazing??? Is this even possible? Is it helpful? I can probably do a leak down test but how will I know if it's the piston rings or the cylinder walls that are shot?

kajtek1

Stephen is a troll with no education on oils. His mechanical experience is not a base for making such conclusions.
Now for engine testing, modern scanners will run "smoothness test" what is comparable to compression test, just way easier to do.

dhurley

If your engine is making proper boost and you don't have an enormous amount of blowby, I honestly wouldnt worry yourself over something thats more than likely never going to be a problem with your vehicle. A lot of the information in that website is anecdotal and based off of sprinters which have an unquestionably harder life than a GL.

GoodByeHonda

Engine power is good. It does loose about a quart of oil per change and I think this is partly because of this seal never being changed.

dhurley

1qt is normal but if you're paranoid, I would look at the plastic CCV before looking at that part.

GoodByeHonda

I did and replaced it with new MB unit. Despite of that, there was always a small pool of oil in the turbo inlet. Now that I replaced this part, no more pool, just vapor over the inlet.

peter2772000

Whereas your opinions count, right? All he did was own/operate an MB repair shop for 30+ yrs. What are your qualifications again? Don't remember....

kajtek1

Well.. unlike Stephen, I did have oil classes and I spend quite a bit of money on doing lab tests.
Now think about it - would successful shop owner seek donation on the internet for his retirement?

Etienne Lau

What plastic CCV are you referring to? That stainless part in the picture is the CCV.....it's bolted to the back of engine.

Etienne Lau

I agree with @kajtek1 Stephen makes a lot of claims on his website but has never provided any scientific proof for some of his claims. I do agree with Stephen that due to the use of low Zinc oil to compensate for DPF contamination has resulted in higher wear and one should change oil sooner than the 10,000 miles/16,000 mile oil change interval.

dhurley

The actual CCV, which is plastic and the rubber valve inside is prone to tears.

Etienne Lau

What you have pictured is for a different engine. It's not what is available for the 2012, 2013, 2014 ML 350 BlueTec OM642 Engine. The non-plastic one is what is available for those engines.

dhurley

No, what I listed is correct. The newer generation OM642 used this as the CCV. Note that the circular body is where the updated diaphram is housed and the outlet where the hose attaches is oval and not circular:


The part the OP displayed is only the metal elbow that connects the plastic CCV to the cylinder head. There are no CCV redeeming properties as its just a metal elbow without restriction. The areas circled in red are where the two parts connect. The OP's profile lists a W211 E320 Diesel, which makes this part era-accurate and not the one above.

Etienne Lau

Good catch on the W211 E320!

dhurley

You know, this has me curious if the newer design can be retrofitted to an older OM642..... hmm bolt patterns look to be the same.

Etienne Lau

Horizontal bolt pattern(2nd Picture) vs vertical bolt pattern(First picture) would probably nullify that idea, as well as potential size difference of the hole where the metal part is attached to the back of the engine.

geniushanbiao

1qt is completely normal TBH. I have a 2015 GL350 and a 2012 ML350 both are OM642. The ML has 96k and the GL has 75k on the clock. The ML is consuming about 1-2qt of oil per change while the GL is consuming about 0.5qt or less, but I did find the oil cooler seal was leaking on the GL so I just tore it down to change the seals (in the other post). Not sure how it will go after the seal replacement. The ML is leaking nothing. I did find the GL's intake badly clogged and I'm probably going to tag along with the ML later if I have time. Don't be too **** about it.