2013 Mercedes E-Class E250 (Petrol). Dashboard Temperature Indicator Signalling Possible Fault
In last 6 weeks, I experienced a couple of incidents of Temperature Indiator reaching 120C within 10 minutes of start-up (after ~1 hr shut down) and speeding up on a motorway; in one incident the dash board messaged to stop and shut/cool down engine. I stopped, switched off engine to reset and then started up within half minute, and the car ran fine after.
Lately I noticed dashboard Temperature Indictor would warmed up gradually to 90C. However when stopped at traffic light the temperature visibly dropped slightly. It also dropped from 90C (where it had stabilised) down to 80C (or even 70C) when I sped up/tested on motorway (cold winter), before it increased to re-stabilise at 90C. If I slow down and then speed up again, the temperature would fluctuate the same again.
I have a garage to replace my Thermostat (which comes with temperature sensor fitted). The temperature fluctuation remains the same. I have not yet re-experienced any 120C incident, but the car has only been back 1 day so far.
Please - any comments anyone. I saw one past report that the Temperature problem could be due to “Engine OIL TEMPERATURE SENSOR” failure/shorting-out. Shall I change the Oil Temperataure sensor to see? I hate to spend more if it is not necessary.
In last 6 weeks, I experienced a couple of incidents of Temperature Indiator reaching 120C within 10 minutes of start-up (after ~1 hr shut down) and speeding up on a motorway; in one incident the dash board messaged to stop and shut/cool down engine. I stopped, switched off engine to reset and then started up within half minute, and the car ran fine after.
Lately I noticed dashboard Temperature Indictor would warmed up gradually to 90C. However when stopped at traffic light the temperature visibly dropped slightly. It also dropped from 90C (where it had stabilised) down to 80C (or even 70C) when I sped up/tested on motorway (cold winter), before it increased to re-stabilise at 90C. If I slow down and then speed up again, the temperature would fluctuate the same again.
- I don’t know if the above temperature fluctuation (according to driving condition) is normal
- I don’t know whether if temperature drop (on speeding up) was due to extra cold wet air on the radiator. The temperature needle was responding/moving a lot according to driving condition; the movements seemed more abrupt rather than gradual. Surely frequent fluctuations from stabilised 90C down to 70C cannot be good for the engine/radiator system - thermal expanson/contraction stresses?
I have a garage to replace my Thermostat (which comes with temperature sensor fitted). The temperature fluctuation remains the same. I have not yet re-experienced any 120C incident, but the car has only been back 1 day so far.
Please - any comments anyone. I saw one past report that the Temperature problem could be due to “Engine OIL TEMPERATURE SENSOR” failure/shorting-out. Shall I change the Oil Temperataure sensor to see? I hate to spend more if it is not necessary.
