I have a 2017 C63S coupe which I have owned for the last 3 years. Because it is not a daily driver, days to a few weeks can go by without driving. Once thoroughly warmed up, the engine oil temperature has always leveled off at 201 to 207 degrees, F. December, 2022 I took the car out and the temp. never went above 177 F. Engine coolant and transmission fluid are both at historical levels, consistent with past experience. Any thoughts would be greatly appreciated. Thanks!

 

Hello,
Did the oil temp never get hotter than 177 F? It depends sometimes on how you are driving. In my GLC63 pushing the car the temp will go to 219 and just cruising the temps will range from 165-190 F. What were your trans temps during this drive?
Thanks

 

Both trans. and engine coolant temps are consistent with previous driving experience. Driving conditions are normal warm up with spirited driving including freeway speeds significantly exceeding posted limits. Trans fluid consistently between 174-179F. Hope this helps.

 

The temps seem good across the board, does the car have a tune? or any other mods like an intake, heat exchanger, etc...

 

The oil temperature is technically in operating range. I believe at 160F and above is operating temperature. That's when it changes from blue to white on the temp display. Transmission I believe is 120F and above. Having said that I never see engine oil temp that low once fully warmed up. It's usually around 201F-207F like you used to see and when driving hard it can go up to above 220F. Transmission generally stays somewhere around 190F. My guess is you may have a faulty thermostat. Oil temperatures these days are kept around 90-100C (~194F-212F) to combat carbon buildup.

 

No mods, complete stock. Superswiss, thanks, I suspected that it might be more "monitoring" related than "mechanical". I have my mechanic getting back to me when I can take it in; any idea the severity/complexity to replace the thermostat. Thanks to all for your help. Love the forum, great info. and help!

 

I've not had to replace it, but it's usually fairly straight forward. The thermostat should be accessible w/o disassembly required.

 

Thanks all, going to mechanic this week. Hopefully routine repair.