Audi's !!!

OP needs new temp gauges and or senders then?

I've ran Rotella in a flat tapped marine engine, never an issue. Also use it to break in roller engines. It's always worked for me and never saw any sludge. In fact marine engines have always been clean as a whistle during normal oil changes.

That's just it. Potentially hit and miss regardless of the said name on the oil. Circumstances etc... Only oil I had a sludge issue was in my first car. 72 road runner and that was Quaker state back then in early 80's.

I wish my first car was a 72 roadrunner, or a duster...haha

Don't know what he has for a cooler. But with the cooler out of the equation i would have to say ditch the thermostat. But that's a guess. Don't know where he is pulling his temp reading from. You really don't need an oil thermostat. If you are getting milky oil from moisture it's because your not running the motor hard enough or there is water intrusion (most likely exhaust).

id keep the oil thermostat ? mecury puts them on all there engines for a reason .. I don't run water thermostats , without a oil thermostat, oil never get hot enough, to run it hard enough to keep oil clean . theres a lot of different setups out there . oil must reach 212 to burn moisture out . it takes my engines 10 minutes of decent running to open my oil stats up .. just saying not judging . you seem very knowledgeable with all youre posts .I read most of yours learning . and listening . thanks

If I read the original thread correctly the OP ran 50 to 60 deg hotter oil temps with oil stats. As far as I'm concerned yes keep the oil stats however go out and run the dogchit out of it a little more frequent. I really don't think you over heated your oil at any point based on what you said. Like black baja said though he's that can and does happen. Kinda like leaving maple syrup on the stove a little to long. If you've never seen over 230-240 plus temps it's very doubtful.

But with this said you still haven't solved anything. You did right by using the oil stats and raised your oil temps to 200-210 but you still have the sludge or possible has been and built up over time. My opinion run the boat harder each trip out and or try different oil. Not saying what your using is bad by any means but it's not working for you from what I see. Also drain your oil rather than sucking it out. Kits from cpperformance are cheap.

I can assure you it never got hot, would have never even known if had not pulled pan...was about 1/2 of muck in the bottom...

Wow. What's your conclusion based on your finds at this point? Maybe call tech line and let them know what your boating characteristics are and the said temps you mentioned and just see if they can come to any conclusion. Would be interesting to see what they say.