It's tough to claim that an engine with a thermostat actuation range of 85-94 was designed to operate below that range.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

94? If your thermostat isn't opening until 94, you have a problem. The hottest thermostat you'll find for these cars is open at 87C. Most older Diesels have 80C thermostats. If the car is running well, it should be "on the thermostat" most of the time.

See the 617.95 FSM. It will tell you that the thermostat does not fully actuate until reaching 94 degrees.

The subject vehicle is a 1982 300D. My comments pertain to that vehicle.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Just an update. I cleaned up the radiator by using garden hose and spraying from engine side. Checked and there was no debris lodged between ac condenser and radiator. I have drained the radiator and flushed the engine with water then used 16oz of shout and water and ran engine for probably 20 minutes or so till got up to 85-90 degrees. Drained system and flushed it twice with water. Added citric acid solution and drove about 100 miles or so and have since drained the solution out. Did notice while on the interstate the temp never got above 85 so not sure if cleaning radiator or if the acid solution opened up the system better. When I drained out the acid solution I was amazed at how much junk came out.

I have now flushed it with water 3 times and have noticed that each flush the water is tinted green like the coolant. Is that normal? Either way I am gonna flush it a few more times with water before adding coolant. Waiting on a radiator drain plug cause mine is now leaking a bit.