PeachParts Mercedes-Benz Forum - View Single Post

G-Benz · #2 04-05-2004, 05:56 PM

The two simplest (and cheapest) things to look for is the thermostat and the expansion tank cap.

The fact that your temp is not exceeding 80C indicates that the thermostat is stuck open...your engine is designed to run between 85-90C and the other management systems use that temp range as a barometer to set other parameters...

...or the thermostat you currently use is too cold (opens too soon). If it is stuck open, when it fully fails, it will close up for good...then you WILL have an overheating problem.

Check the condition of your coolant cap. It's designed to maintain pressure. If you aren't overheating, it's probably doing it's job, but it may also be the incorrect cap pressure (too high, which would result in lower temps, but excessive coolant pressure).

Both the cap and thermostat run about or less than $30 (even at the dealership). The thermostat should be the 87C version, but I can't remember the BAR specs for the cap...