RS5 Oil Temperature Rise

A5/S5/RS5
#1

I’ve noticed a recent increase in engine oil temps on my B8.5 RS5 and wondered if anyone had any ideas ?

I constantly monitor temps and up until about a month ago I was sitting around 100 deg Celsius during normal driving and 102-103 with spirited driving. Recently this has risen to 102-103 normal and 105-107 spirited ?

It’s not atmospheric conditions as we’ve actually been quite cold (by our standards) recently

I’ve seen heaps of discussions about the Integrated oil cooler for the transmission but does the engine have a stand alone oil cooler and what can cause this to not operate so well ?

Also it’s not oil level as it’s at about 90% full

#2

Sorry for not replying to this earlier, I think I just missed it.

The oil will run hotter the cooler it is outside. So a) you’re not crazy and b) it’s perfectly normal. It sounds counter-intuitive but it’s how it operates.

I did a long road trip years ago and noticed it then. I’d leave early in the morning with the temps in the high 60’s to low 70’s and my oil temperatures would be 10-15 degrees higher than at say 3pm when the ambient temperatures were at their highest. Here in Texas, when it’s over 100 degrees Fahrenheit, my oil temperatures are usually around 203F (95C). I’m also running the RMR trans cooler with the cross bar so I do get a bit more airflow.

#3

Completely normal.

We’ve had a stretch of 32-35 degree weather here and my engine oil is COOLER. Running between 98-103 and I’m normally around 105-110.

I DID NOTICE HOWEVER, that when I had new coolant put in, and the RMR cooler/crash bar my oil temps consistently are 5-10% cooler.

I’ve seen oil temps as high as 118, and before the RMR cooler it usually sat between 108-112 at 20 degrees ambient temps. It now sits anywhere between 98-105.

#4

Thanks guys