Running to hot!!! Maybe???
 

Had the water pump go on my 330SDL. Caused in part by something the previous owner had used for radiator leak seal I am thinking.
Anyway, replaced the thermostat and water pump. Ran just watr in the engine for about three days and temps were at 84-86C, put antifreeze back in and the temps go up to around 100C and idle in traffic gets close to 120C. I am thinking perhaps the crap they used has partially blocked the radiator as well. I found about six inches of the radiator hose going to the thermostat almost pluged as well when I changed the parts out. Does anyone have any suggestions other than radiator, I can find one or have this one redone. Could it be a bad fan clutch??

Thanks to anyone for their help!

Ric

That is a little too warm. Is it running a solid 100C on the highway with low outside air temps? If thermostat is good and temp gauge is working properly, there might be the possibility of a flow problem. To test the fan clutch, with the engine running that warm you should be able to feel a large volume of air being blown by the fan when you open the hood, especially when it is reved. Just be careful to keep your hands clear. If there is no mass airflow from the fan at those temps, the fan clutch may be suspect as well.

If I read it right, you're temps went up ~ 15ºC when you switched from plain water to an ~ 50/50 water/MB coolant mix and nothing else?

Plain water is better at heat transfer, but, that's a big difference.

I'd suspect the coolant system isn't "burped". Run the heater, disconnect the top rad hose and whatever else you may find in "search" using <burp> or <burped> as a keyword. FWIW ;)

change radiator
 

my guess is the radiator is clogged. The capacity to transfer heat is not there.

I will have to check the fan volume this morning. I did in fact do a burp so to speak after a stop it took a resivior full of coolent.

But the biggest thing I believe shows radiator. We drove into Spokane last night and the further we drove the higher the temp climbed. Until we turned the heater on, it then dropped a little and stabalized, putting the blower on high brought it down to 100 where it remained as long as the heater was on hi and the blower was wide open.

Thanks