PeachParts Mercedes-Benz Forum - View Single Post - Overheating, with no leaks and no thermostat

PDeputy · #10 08-13-2004, 07:53 PM

Some updates,

Did the majority of the checks recommended. Warmed the car up and checked the radiator, it was hot from one side to the other and from the top to the bottom. Still have both belts to the water pump and both are tight. No oil in the coolant, no coolant in the oil (bubbles). Unsure as to whether I have air pockets or not, still could be some. (Since then I have read threads on this and will make sure to "burp" when I replace the fluid). Tried another diagnostic test, pulled the top hose (small) from the resevoir to the radiator and let it drain in a jug while the engine idled. What came out was mostly a frothy liquid, it sputtered and sometimes nothing came out for 10 seconds. I expected a small but consistent stream of coolant. Remebered that when I removed the old thermostat no fluid came out of the housing (or connected hose). Seemed odd, like maybe an air pocket?

Then the suprise showed up this morning. Coolant on the ground under the engine. The water pump is now leaking! I would have thought the leak would have been noticable when the overheating started.

I ordered a new water pump and thermostat. It will take a few days to arrive. After I replace will update.

My explanation now is that maybe the thermostat was sticking and then the water pump stopped pumping properly (not circulating the coolant fast enough to prevent overheating).

Anyway, will keep everyone informed and thanks again.

PMD