Hi all,
I've had my E63 (m156) for over 3 years and the oil temperature under normal driving has never surpassed 212F to 100C. A few days ago randomly, the temperature on the same exact route starting going up to 217-219... and under hard driving, it would rise much faster than usual to over 235... before, under even harder driving... it wouldn't pass 221f.

I noticed that the oil fan cooler is not turning on... but I am not sure what temperature it usually kicks on. I checked at 226f and it was not on at all. Can anyone help with diagnosing this issue?

Thanks!

 

Any ideas?

 

Maybe the fan motor has gone bad.

 

I figured - How do I test? I have an MBII scanner and there are no codes... I checked fuse F75 in the trunk... and seems ok. Any ideas?
Thanks

 

Anyone??

 

 

I'll look into that.. but the temperature seems to be in the range of what is considered normal.. I am just surprised that it no longer stays in the same exact range as it usually has. Does anyone know how I can test the oil cooling fan?

 

My M156 in my 2011 E63 runs normally between the range of 197 - 225 degrees. It seems like your are in that same range, I am curious does the car run differently or the same, at the higher operating temperature?

 

runs exactly the same. I know my car is still within the normal range. It just never ever passed 212 during the same exact daily route since I've owned the car and all of a sudden ... it does. It hits 217 -219 under similar loads then slowly drops to 212..or 213... Almost like it's not cooling fast enough or the thermostat is sticking.

 

 

Yes it does and that works perfectly fine. It's a seperate system from the oil cooling system.

 

My friend just bought a 2015 E63S 4-Matic and he was have issues where the oil temperature was reading off and random. He ended up taking it to the dealer earlier this week and they found out that the oil temperature sensor was faulty and he is waiting on it to arrive at the dealer and was covered under warranty.

 

Finally figured out what was wrong... or not wrong.....
here it is.. the weather has been cooler lately and I've been turning my climate control off. When I do that... the engine temp oil temp goes up to the 215-221 range... when I turn my climate control on... the engine runs at 204-210 on the same exact route...the coolant temp is always at 195 on non stop go traffic. I'm not sure how they're related. because the condenser fan is the radiator fan... which does not cool the oil. But either way..maybe the oil thermostat opens up quicker when the AC is on? If anyone knows or has a theory... would be great to understand better. Either way... not concerned anymore.