Oil temp question

[dparm]

Originally Posted by ethan9273

I would like to revive this thread as I have an 08 e92 m3 with these exact same scenario happen to me today In very easy going temperatures 23C in California going backroads uphill Hans driving. Somewhat hard. My question is, I don’t find this ok or comfortable. What can I do to make things better? New oil cooler???

Oil temps will rise when you drive the car hard. I would not be worrying about it until you're past the ~270 mark for extended periods. The car and the oil can take elevated temps -- it's made for that kind of use.

Why don't you find this okay/comfortable?

[wrk.eat.drive.rpt]

Agree. I just see a lot of seesawing of info.
Mostly because I’ve seen a ton of posts where
1. This only happened after xx years of it never reaching past 210 regardless of how it was driven and then suddenly temps are rising. That would be a classic case of out of the norm behavior for the cad
2. A couple posts saying that they saw an early warning sign of increasing oil temps when they hadn’t prior and end up woth a blown main bearing

[wrk.eat.drive.rpt]

Plan to clean out oil cooler and see where that takes us

[pbonsalb]

Remove it and use radiator fin pliers and a thin screwdriver to straighten out the outer fins. Let us know if you get a bunch of junk when flushing it. I tend to think there won’t be any.

[wrk.eat.drive.rpt]

ok... update. the oil cooler WAS dirty.. Completely cleaned out. That said.... temp issue is STILL there... Sigh..

Not sure what's next.

[kyrix1st]

Originally Posted by ethan9273

appreciate the feedback and I've definitely searched other threads, I responded to this one because the scenario is the most similar to mine...
From the threads I've searched I can't seem to find a reasonable conclusion. anything from
1. It's fine/normal.
1a. It's not normal (drive on track at over 100 degrees and never went past 210)
2. water pump/thermostat
3. radiator or oil cooler needs replaced/updated.
4. Coolant issue
5. Early warning signs of bearing failure.
6. Fan etc.

If this is in fact normal I can live with it. but being uncertain and going on middle of nowwhere 200 mile backroads drives makes things feel very dicey.

Any additional help will be greatly appreciated.

As for 1a, high speed circuits typically produce better frontal cooling thus your engine is able to sustain 100C at moderate load.

On mountain roads or twisty circuits however, you either don't drive fast enough for air to cool or drive too fast in corners for air to really make their way into the engine; thus it is totally normal to see around 115C.

Good example of high speed twisty circuit is Suzuka. I see 120+C during the spring with Motul 300V 15w-50.

I think you should instead admire how efficient and stable S65 engine is. Laws of thermodynamics state that heat efficiency is higher for a hotter engine because that means there is less energy loss from heat dissipation. It is in the same context as to why modern F1 engines that record over 50 percent power efficiency run much hotter than typical gasoline engines.