After a new radiator was installed the temp climes to 80c very slow and sometime sits at about 60c for a long time. I de oiled and flushed several times then with citric aside to clean the rust from the block. Filled with 50/50 water and MB antifreeze. Is there air trapped in the head so the temp gauge is out of the water or is the new rad that much more efficient.

A second problem that came along. With the 50/50 mix in the car, the water pump leaked. When I remove the 50/50 mix and fill with fresh water no leak. Had no leak befor new rad installed.

This car is driving me goofy.

Much appreciate any ideas.

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1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

Replace your temp sensor in the cylinder head.

I'm not sure as to why it would leak with the mix and not without. Don't use straight water for long, it must be a 50/50 mix.

How's your t'stat? Can't help either with why leaking with a mix. I had a water pump that would leak sometimes, then all the time, never did figure it out, but had to replace it.

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83 SD

84 CD

Not to be too obvious, but the slow heating symptoms you describe are of a car with no thermostat installed (or possibly a stuck open thermostat). Assuming that the temp reading on the dash is correct.

The waterpump leak probably has nothing to do with the coolant composition, but may have resulted from unblocking sludge/scale during the flush process. Try to think of it as a good thing, at least a waterpump and its gaskets are relatively inexpensive (provided that your labor is free).

It's a pretty safe bet that the shaft seal had exceeded is life expectancy. Such is the fate of any water pump that remains in service long enough.

Thanks for the input. I will replace the water pump, only 65 bucks.

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

Sounds like a new thermostat would be a good idea, also. Then there's the bypass hose...