1983 300d Running Warmer than Normal lately - PeachParts Mercedes-Benz Forum

Sev · #1 01-17-2014, 10:43 PM

1983 300d turbo
Lately after driving about 5 minutes or so in about 70 degree weather, the temp gauge is showing high 90's to low 100's. As soon as it hits 100 I panic and turn on the heater and it goes down by a few degrees. As long as I've owned the car, about 15,000 miles or so of driving, the temps have normally maxed out at around the mid-90's except in very hot weather of 100 degrees or so. What I'm thinking of doing is a coolant flush (flushing all fluids but not doing a citrus flush), and replacing all hoses in the engine bay along with the thermostat.

I don't know when the last time the coolant was flushed, but the car has 290K miles on it and I've had it since 275K miles and never done a coolant flush myself. If that doesn't cool things down I'm thinking about installing a flex-a-lite fan like the diesel giant diy. Any thoughts on my little plan to cool things down a bit?

whunter · #2 01-17-2014, 11:15 PM

If this has been a sudden change = replace the thermostat FIRST..

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Sev · #3 01-18-2014, 03:04 PM

Quote:

Originally Posted by whunter

If this has been a sudden change = replace the thermostat FIRST..

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Ooh. So why the thermostat first? Am I just eliminating that as a failure point? I took the car in to my mechanic today. He's doing all the aforementioned service. Do you think it will bring the temps down to what it was?

whunter · #4 01-19-2014, 06:06 AM

Quote:

Originally Posted by Sev

Ooh. So why the thermostat first? Am I just eliminating that as a failure point? I took the car in to my mechanic today. He's doing all the aforementioned service. Do you think it will bring the temps down to what it was?

The thermostat is cheap, and the most common cause for this issue.

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delwood47 · #5 01-19-2014, 11:44 AM

I had the same problem with my 1983 300D. I flushed the system and installed a new thermostat. I also added Redline Water Wetter. This fixed the problem.

whunter · #6 01-19-2014, 05:51 PM

Quote:

Originally Posted by delwood47

I had the same problem with my 1983 300D. I flushed the system and installed a new thermostat. I also added Redline Water Wetter. This fixed the problem.

Anyone in the snow belt should NOT use this product..

Water Wetter becomes slush or Jello below zero = no coolant circulation = blown engine...
Is Antifreeze, like Aspirin, "Hype"?

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Sev · #7 01-23-2014, 02:55 PM

The verdict is in: paid $140 to my mech for coolant replacement (not full flush) and all hoses & thermostat replaced. The car now runs in the mid to high 80's!