Is this contaminated?

Messages
7
Good evening,

This is a sample of my engine oil, 5w40 Mercedes Benz. Approx 3000 miles old, after a quick stir it has this lighter brown colour to it. I am suspecting coolant/water contamination. Is this what it looks like at early stages? Anything else I could be missing? I don’t believe it’s normal?

Many thanks
BCA88D5F-207C-43D7-A5CC-EED4CE5FA461.png
 
Messages
1,391
Location
USA
difficult to observe any issue from that picture.

If possible in a glass/clear container with a light shining through from the side and after settling on the bottom.

Also a drop on a white blotter and lets see the dispersal and rings
 
Messages
1,238
Location
PEARL River la
Looks normal to me. Oil has to hold deposits then when you stir some will release but will be held in suspension once it heats up. You also could have fuel dilution but you would have to send it to a lab to determine what or if is in oil.
 

Dannyfiveforty

Thread starter
Messages
7
Thanks for prompt replies!! I have the notorious m156 engine with headbolts that can (and often do) fail.

I can get some more pictures of the sample tomorrow. Coolant level has dropped in the expansion by approx 10mm, oil level has risen slightly. I check levels by habit every other day between uses. I have noticed the level changes the other day and extracted a sample. I intend to get it analysed by a specialist company but want an opinion on the brownish swirls I get with a quick stir..

Many thanks, great forums btw
 

Dannyfiveforty

Thread starter
Messages
7
Have you cut open or inspected the oil filter (if a cartridge type) see see what's been caught?
No I haven’t, but I can do this tomorrow and report back, are you suggesting I might find unusually large debris in there? (The silver flecks you can see in the picture are bubbles, not metal).
 
Last edited:
Messages
24,818
Location
PNW
No I haven’t, but I can do this tomorrow and report back, are you suggesting I might find unusually large debris in there? (The silver flecks you can see in the picture are bubbles, not metal).
Looks like more than bubbles. It looks like oil as a motor breaks in - super fine metal/aluminum particles that normal oil filters can't catch. My suggestion is to inspect the oil filter to see if there are any signs of the motor wearing abnormally for some reason.
 

Dannyfiveforty

Thread starter
Messages
7
The problem I have is I have no comparison, or anything really to show normal. The company were very helpful and talked me through some key points, they don’t like to see 100ppm of iron or there abouts, I guess it does all depend on the age and use (mileage) of the oil.
 
Messages
43,331
Location
Ontario, Canada
The problem I have is I have no comparison, or anything really to show normal. The company were very helpful and talked me through some key points, they don’t like to see 100ppm of iron or there abouts, I guess it does all depend on the age and use (mileage) of the oil.
Iron tracks with mileage and the typical condemnation point is ~150ppm, but that's with very long OCI's. The fact that you are 1/3rd of the way to the condemnation limit in only 3,000 miles is, in my mind, concerning.

What's the condition of the air intake tract? Silicon is also a bit high at 30ppm, assuming it's not part of the lubricant, so it could be from dirt ingress, which would also explain the iron.
 
Messages
24,818
Location
PNW
The problem I have is I have no comparison, or anything really to show normal. The company were very helpful and talked me through some key points, they don’t like to see 100ppm of iron or there abouts, I guess it does all depend on the age and use (mileage) of the oil.
Except his car has 90,000 miles on it and the oil was used for 3,000 miles. If it is iron particle swirls in the oil then have to ask why on an engine with 90,000 miles.
 
Top