280CE coolant flush and M110 thermostat change

The 280CE had been performing well on the road after being put back into service, but the most obvious issue was that it never got up to operating temperature.   Running too cool is not good for the engine and also results in higher fuel consumption.   As they say, overheating an engine might kill it instantly, but underheating it will kill it slowly.     The theory was that the thermostat had jammed open, which is the most common failure point.   Despite what you hear, the car should never be operated without a thermostat.   Some people in hot climates drill a few holes, but the thermostat is an important part of the cooling system and should always be present.

The M110 thermostat is quite easy to remove – three 10mm bolts hold the housing – one is harder to get to and easier with a 1/4″ ratchet and extension.    Care should then be taken to align the new thermostat correctly – i.e the little valve at the highest point.

The thermostat change did the trick – the car is now running around 80c instead of around 60-65c and after a flush has fresh coolant.   We did an oil change too.  The M110 thermostat is much more accessible than some of the other cars, making it an easy change.