Mobil 1 0w-40 in Mercedes diesel

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Hi all,

I am trying Mobil 1 SuperSyn 0w-40 in my 1987 300D. This is 3.0L 148 HP engine indirect injected (prechambers) with 9 qt sump. At the time of the sample the engine had 271,000 miles.

miles on oil 7911
miles on unit 271063
visc 100C 13.89
TBN 9.78

Fe 40
Cr 2
Pb 2
Cu 1
Sn 0
Al 6
Ni 0
Si 6
B 71
Na 17
Mg 145
Ca 3121
P 997
Zn 1108
Mo 42
Glycol neg
H20 0
Fuel Soot 0.82%
Oxd% 19
Nox% 17

I have taken many analysis on this engine, running the oil between 6500-9500 miles. For this sample, Iron is twice as high as usual from all other samples from Mobil 15w50, Delvac, etc. Sodium seems high for some reason, so I am wondering about an induction leak. Soot is 1/2 the usual amount, so I am wondering why. I haven't touched the engine. Does cold weather have anything to do with it? Only thing I've noticed is small exhaust leak in a flex pipe near the turbo/manifold.

Comments, opinions welcome!

Thanks,
 
It seems to be quite the trend on here lately that iron is high in all the recent analysis, and I do believe the cold weather is the culprit. I bet your analysis results in the summer show drastic differences in iron.
 
Mobil 1 0w-40 meets current Mercedes spec 229.5 and also Euro ACEA B4-02 for use in light-duty diesels, so I was trying it out for comparison. The Mobil 1 15w-50 meets 229.1 and B4-02 and seems to work as well as Delvac 1, at least under the circumstances of which I ran it.

Brian
 
The oil held up very well in your turbo MB with very low oxidation and little shearing. The TBN still looks good also.
 
quote:

Originally posted by brian:
Mobil 1 0w-40 meets current Mercedes spec 229.5 and also Euro ACEA B4-02 for use in light-duty diesels, so I was trying it out for comparison. The Mobil 1 15w-50 meets 229.1 and B4-02 and seems to work as well as Delvac 1, at least under the circumstances of which I ran it.

Brian


MB diesel specs are 228.1, 2, 3, or 5.


Ken
 
Brian,

Sodium and Potassium are also trace elements in most Ethylene Glycol based antifreeze, so I'd keep an eye on your cylinder head gasket. I believe the actual test for antifreeze contamination will only come out positive if the # is > 0.5%, so looking for trace amounts of these other elements is a more sensitive technique. A trace amount of sodium can also come from road salt or from biodiesel fuel - ie: used frenchfry oil which has been esterfied. I'm sure you have seen the latter on the TDI forums?

The 0w-40 actually held up better in your Mercedes than it does in gas engine applications, particularly with regards to shearing. However, as I recall, the Delvac 1 wear rates were significantly lower....
 
Another thing to keep in mind is that many Borates (AW's and detergents) are in the form
of Potassium Borate, so some Ka can come from that that as well.
 
There was no Potassium in this sample (tested zero).

The most current MB specs for all engines, gas and diesel, are 229.1, 229.3, and 229.5. This information is available in the MBUSA document MB Factory Approved Service Product List.

Regards,
Brian
 
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