tmryan

Where is this sensor located. Is it in the front of the motor by the thermostat or at the left rear on the motor?

Thanks

konigstiger

Motor, left rear.

tmryan

I have a 2010 Mercedes E350 4 matic 76,000 miles that when I drive the temperature usually runs at 90 degrees. Lately the temperature will spike to close to 120. If I shut off the hvac system, the temperature quickly returns to normal The gauge returns to normal range very quickly. There are no cel codes or lights. Problem occurs randomly and the car drives fine with no apparent overheat issues. At highway speeds car stays at 90--problem occurs after exiting highway and sometimes during local driving. No noise or leakage from water pump. Would a failing wp cause this?



The thermostat was replaced last year with an OEM part. I have "burped" the cooling system several times with no improvement. Condition reappears. Since the conditions corrects itself when the temperature control panel is turned off, I am thinking it might be the temperature control sensor. Using my icarfoft reader i get code 0485 "coolant temperature high" Cannot find any info as to how to correct.


Any ideas appreciated.

Sunnyslope48

https://www.autocodes.com/p0485_mercedes-benz.html

tmryan

Thanks for the code information.

It looks like the engine temperature could be the problem.

Would a failing ect cause the temperature spike. What are the symptoms of a failing ect?

Part is fairly inexpensive. Any "tricks" to install?

Thanks