Rising oil temperature and shifting

hyunsoo1803

Ok, this is my first manual transmission car that I own.

I've been driving this car for more than a year and havn't noticed any problems with oil temperature rising over 90 C.

IMO, major change occured after I changed my intake/exhaust.

I installed stillen gen 3 CAI and invidia gemini CBE which I loved a lot.

Since then, after a month or two, I noticed slight increase in oil temperature and it went on and on and it reached 115~120 C (where I haven't revved it above 3000)

I was wondering why and I thought, maybe I should get a oil cooler (which made me buy a stillen oil cooler) Before the product arrived, my friend noticed my engine coolant was empty; then I refilled it then solved the oil temperature problem a bit.

After the oil cooler install, the oil temperature stayed at around 75 C.


Now, here is a question, the oil temperature was supposed to stay around 75 but when I drive around in the city, (where it makes me shift up and down a lot,) the oil temperature rises roughly about 90 C. But when I enter highways, the oil temperature significantly drops roughly to 80 or even 75 C.
Am I shifting gears wrong? during the first year I drove around with my Z, the car was perfectly fine, and after some mods, the car seems more sensitive somewhat from my mistakes.

Any suggestions? Engine oil? transmission oil? Nismo Clutch&Flywheels?

P.S It's possible my clutch has been abused due to my first MT car, friends (a lot of abusing I believe, and etc)