Thermostat Replacement on a 2010 Mercedes-Benz ML350 is our latest featured service, brought to us by a client from Richmond, BC.
The thermostat is a key component of your car engine’s cooling system. Its function is to keep the engine at the minimum operating temperature, usually around 90 C (195 F). Generally a thermostat is a simple component that opens and closes at the specified temperature. Two things can go wrong: it can stick shut causing your engine to overheat, or it can open too soon and/or stick open causing a slow engine warm up. The later was the cause of concern with our featured 2010 Mercedes-Benz ML350.
If you are wondering, how would I know if my thermostat was faulty there are signs. First off, the most serious concern is a stuck shut thermostat. Your engine will rapidly overheat and you will know this by looking at your temperature gauge and your engine may be blowing out steam under the hood. If any of these symptoms occur, shut off your engine immediately and have the car repaired.
A stuck open thermostat can be more difficult to notice but there are signs. During winter in a cold climate you may have little or no heat in your vehicle. Your temperature gauge will also read low. On many modern vehicles the powertrain computer monitors the engine warm up cycle and if it is too slow will turn on your check engine light and store a trouble code. That is exactly what happened with our featured Mercedes-Benz ML350. Having a diagnostic system that monitors engine warm up is great because it provides you with an early warning of this concern. When your thermostat sticks open your engine never runs at optimum conditions and wastes fuel. High emissions are also a result.
On this vehicle we needed to verify that the concern was a stuck thermostat. After reading the code we road tested the vehicle with our scan tool and monitored the engine temperature: it never even reached 70C (158 F) after a long drive. This is a far cry below the specified temperature.
After replacement of the thermostat we road tested the vehicle and found the temperature rose to the high 80s Celsius quickly. Our repairs were a success and with cold winter temperatures on their way our client has the benefit of a vehicle that warms up quickly, as it should.
For more about the Mercedes-Benz ML350 click here http://en.wikipedia.org/wiki/Mercedes-Benz_M-Class
For more about automotive thermostats click here http://en.wikipedia.org/wiki/Wax_thermostatic_element