Best top-end rebuild threads you will find on the 'Net for each respective motor.

Funny
 

Nice GIF - provides a good analogy => you need a lot of heat to burn off grease / oil

As I asked earlier - what's the exhaust manifold like?

If that is getting gunked up with goo too then the oxygen sensor will probably start to struggle and the catalytic converter will get less and less effective and eventually you'll end up with annual emission / exhaust gas check test failures.

Whilst you could argue that all old cars end up with this trouble and that "they all look like that" it doesn't mean it is "normal" - you might say it is "commonly found" - but that doesn't mean it is OK.

I consider it to be a point of concern.

I guess if the external leaks are eliminated then I can check oil Consumption internally properly. Prior to the leaks I had no oil being burnt. The Gasket Could Have Been Leaking Both Internal And External...Who knows. We will know going forward though.

Do you think I should put some sea foam through her to clean it up a little?

If you mean Seafoam, or a good injector cleaner like Red Line SI-1, in the fuel... it won't hurt anything. Don't expect magic results either. If the injectors are original, the best thing you can do is replace them. The mechanical injectors don't last forever.

DO NOT put any additives in the oil / crankcase.

:nuke:

With the current condition of my valvetrain being so clean, the delo 400 oil I use seems to be doing the trick.
I was going to do seafoam right into the intake manifold via the ezl vacuum line...

On another note -- I had a realization about the carbon. I was running a 79C thermostat all winter, so I wonder if it was simply the reduced coolant temps? I put a regular 87C back in, so maybe that will do the trick.

I have run DELO 400 LE (15W-40) in my E320 for the past 4-5 years with no problems. I use 2,000 mile OCIs. Generally I have used Mann and Hengst oil filters.

The cleanliness inside my engine, with 201K on it at the rebuild, shown in my photos speaks for itself.

Seafoam and other engine "cleaners" are NOT needed with any MB engine. I am not a fan of any sort of additive to MB engines save for things like RedLine Water Wetter (if needed) and the like. If you use Chevron gasoline with any regularity, even good additives like Techron are unnecessary.

Cheers,
Gerry