Under Valve cover photos

[loneryder]

Black is usually good, means it's doing its job keeping things clean.

Black oil means the engine is dirty. Or you don’t have an air filter.

 

[gogydm]

I have to agree with all of you but why does only one brand get very dirty in my car? Same oil behaves very differently in another Mercedes but with a M271 EVO engine. Never gets as black with almost twice the mileage between changes.

 

[OVERKILL]

Black oil means the engine is dirty. Or you don’t have an air filter.

Or it's an engine that just has a tendency to generates a lot of contaminants. My 6.4L is one such mill, as was the S62 in my M5. In that case, the oil being black is it doing its job and flushing those contaminants out by keeping them in suspension.

 

[OVERKILL]

I have to agree with all of you but why does only one brand get very dirty in my car? Same oil behaves very differently in another Mercedes but with a M271 EVO engine. Never gets as black with almost twice the mileage between changes.

That engine may be cleaner inside, or doesn't generate as much in the way of contaminants. As I mentioned, Mobil specifically calls out their 0w-40 as being able to clean, this is due to the ester content. If that engine has some accumulation inside, this oil may be cleaning it out, causing it to look darker than the other oil, that isn't providing that same function.

 

[Gene K]

Good question. No Idea. It's an alum., 32 valve, 16 spark plug, dbl OHC engine. Precursor to the AMG engine. Very fast car.

That looks more like a SOHC 3V than a DOHC 4V. Not that I know anything about MB engines.

 

[OVERKILL]

That looks more like a SOHC 3V than a DOHC 4V. Not that I know anything about MB engines.

Yeah, @2EHA posted the underside of the head on the previous page. Dual ignition like the HEMI, SOHC, dual intake valves, single exhaust valve per cylinder.

 

[Gene K]

Yeah, @2EHA posted the underside of the head on the previous page. Dual ignition like the HEMI, SOHC, dual intake valves, single exhaust valve per cylinder.

Apparently MB did a better job with that design than Ford.

 

[slo town]

OP, the apparent cleanliness of that motor is remarkable!

Scott

 

[loneryder]

I have to agree with all of you but why does only one brand get very dirty in my car? Same oil behaves very differently in another Mercedes but with a M271 EVO engine. Never gets as black with almost twice the mileage between changes.

Air intake leak??

 

[2EHA]

Apparently MB did a better job with that design than Ford.

and it saved them a lot of money.

it was a "modular" family like ford originally wanted theirs to be. v6, v8, v12

 

[loneryder]

Thought it was 4 valve. That explains the valve train configuration.

 

[OVERKILL]

Apparently MB did a better job with that design than Ford.

Yes, I agree!

 

[gogydm]

Air intake leak??

I somewhat recently replaced the intake manifold due to the the rods that control the flaps breaking. All looked good. All new vacuum hoses too.