450sl Operating Temp

[UPSTATE NY]

Hello. I have a 76 450SL and I'll be damn if I know what normal operating temperature is. I'm concerned about damaging the engine with it operating to hot.

The car runs at 175 +, put very rarely does the temp gauge hit the mark between 175 and 250. I think this is 212 degrees because this is when the aux. coolant fan comes on.

That said, how hot can this engine run without doing damage ?

Thanks for any input.
JOB

[kitchenrat]

you're running at normal operating temp. these old 450's are cold blooded motors. mine runs at or under 175 except when ambient air is extreme or under loads from hills which takes it to just under the next mark. as far as what temp would hurt it is concerned, i don't know the answer, but that's what the top number on the guage is for. if the needle hits it, time to shut it down and fix something.

[Roncallo]

Originally Posted by UPSTATE NY

Hello. I have a 76 450SL and I'll be damn if I know what normal operating temperature is. I'm concerned about damaging the engine with it operating to hot.

The car runs at 175 +, put very rarely does the temp gauge hit the mark between 175 and 250. I think this is 212 degrees because this is when the aux. coolant fan comes on.

That said, how hot can this engine run without doing damage ?

Thanks for any input.
JOB

It sounds like its running perfect. I get up to about 220 on hot summer days with my alloy block 560SL.

John Roncallo

[al76slc]

Have you checked your coolant mix? Mine was way off when I bought my 76 15 years ago. My vehicle would run hot frequently. Since the first coolant flush, and replacement using 50-50 (using only MB coolant), I would guess I'm consistently running about 25 degrees cooler. I've used Water Wetter sometimes, but can't confirm that it helps.

[page62]

Hitting the "212" mark is nothing at all to worry out. Start worrying when the car hits the temperature redline!