Oil temperature hotter after once heated?

filip00

I tried to search this issue but haven't found it.

At normal driving my oil temp is always around solid 90°C (194 F). I went for a track day where I had 3 runs in total, with not more than 5mins of faster driving, where my oil temp always reached a max of 125°C (260 F). Each time I left the car to cool down and all is well.
However, now after this I noticed that my normal driving temp is now always about 100°C. Does this mean that I've "burnt" the oil? I.e. is the cooling capacity of the oil destroyed?
My gallery gaskets are aftermarket, changed last year, oil color seems perfectly fine, no loss of oil, engine working perfectly, all good and no symptoms. It's just that normal oil temperature is now higher.

This EXACT same thing happened last year when I also went for a run on the track, where I wasn't pushing the car a lot, and I didn't exceed oil temp into some crazy numbers. Since then I changed the oil and it was fine, until now, again when I reached higher temps.t

I'm just worried why the sudden difference in running temperature, is this normal, is there anything I should check? Did I break down the oil?

For reference, It's Mobil 5w30.

Thanks!

ZoomZ

Check the temp sensor against a known value. The FSM may have those numbers.

SouthArk370Z

My guess is that the oil has changed a little bit, from use, and is not transferring heat quite as well. Or it could be the filter has clogged up and is reducing flow through the system.

First thing I would do is change oil and filter. If that fixes the problem, I'd quit worrying about it. YMMV

If changing oil/filter doesn't work, I have no idea what the problem might be.

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filip00

Yes, that's what resolved the same exact symptoms last year. It was also after a track day, and also normal running temp was higher, and when I changed oil and filter, it was all back to normal again.

I suspect it's the same now, but what that tells me is that probably the oil isn't that good, or I managed to kinda destroy it.

Thanks!

THE BULL

Any oil cooler?

Technically after a spirited run oil should start seeing some fuel dilution.
An oil change to the same weight will confirm this.

Are you tuned?

Excessive rich AFRs will dump fuel into the crankcase and dilute the oil. Diluted oil will stay warmer.

Are you running a circulated catch can or stock PCV system?
If your PCV is open to atmosphere then vapors will hang in the crankcase exacerbating the problem.

A circulated system will be pulling some of those vapors out of the crank case.

Start with the changing of the oil along with putting this oil through the ringer and observe operating coolant temp oil temperatures.

You should start seeing higher oil temps over time.

filip00

I don't have an oil cooler yet, and nor did I tune the car. It's all stock.
I'll change the oil soon and follow up on this. Thanks guys!

THE BULL

Nothing you do will get rid of this unfortunately.

If you own anything with a VQ and drive it like it's meant to the oil temp WILL go up. Start looking for an oil cooler.

Rusty

If you are tracking the car hard. Get a 34 row oil cooler.

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