OK, now I think I might have another problem as well. I previously thought that the fan clutch also engaged the water pump, but after reading Matt L's post I realized that this would be silly, since the water pump is an essential part of the cooling system and shouldn't ever be disengaged. Even if the fan is stopped, the water pump should still turn.

This leads to my new concern. Immediately after getting the car home after the overheating incident, I felt the radiator and it was COLD. This says that no fluid was passing through radiator, suggesting a malfunctioning water pump, or perhaps a stuck-closed thermostat.

How do water pumps fail? There is no sign of fluid leakage in the area. Is it possible for the impeller to come loose from the shaft?

Can thermostats stick closed? A new thermostat was installed in the spring (because the car ran cool) and has run at 80degrees since, reaching 90 only sitting in traffic in the hottest weather.

anything else?


thanks for your help!

Paul

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1998 E300D 1-tank Elsbett Veggie system
1986 190D 2-tank Veggie system -Sold