Advice Needed - High Oil Temperature when cruising!

[nitekid]

Hi guys,

I am from a tropical country Singapore and have recently encounter a engine oil temperature issue which even my mechanic could not figure out, hopefully i can find the root of the problem with all your gathered experience and knowledge on S15.

Here it goes -

When i am cruising around 100km/hr regardless if its morning, noon or night, my defi oil temp would slowly rises to 100degree C but strangly defi water temp maintain to a steady region of 80 - 89degree C. When coming to a stop or if there is a traffic jam, oil temp would then steadily go down to around 90degree C.

So basically the main problem is only when cruising/travelling, oil temp will rise and hit the 100 mark whereas it use to be at the region of around 88degree C to max 92-93.
The weirdest part is, it does not increase when i am stuck in a bad jam with very hot weather only when cruising/travelling will the oil temp increase. My mech and friends was telling me that usually the water temp would rise higher 1st causing the oil temp to increase.

What i have done so far, was to flush my radiater to make sure there is no choke, adding fresh coolant in, changing temp sensor to make sure its not faulty and even changing to a new water pump but all these apparently didnt work.

So what may seems to be the problem?

- Fan clutch weakening? bearing slightly jam causing the fan to not be as strong when cruising?
- Head casket? - which i doubt, no flooding on my reserve water tank.
- Thermostat? - Hoses feels fine and heat normally.

Thank you all for taking the effort in reading and would appreciate for any helpful advice. Cheers

 

[tooley]

Upgrade to an oil cooler!

Ceck for air locks.

I had the same issue when crusiing over 100MPH and my oil would reach 130 degrees when drifting etc.

I bough a 16 row oil cooler and a upgraded radiator and she is now all good

 

[TurboAL]

difficult one to say. have you got a water temperature gauge to compare the two? Oil temperature is closely related to water temperature. Mine tends to see a 10degree differance I would defineatly check you thermostat.

 

[craig8585]

I was thinking thermostat too. It may not be opening fully - I had this exact problem on a different car a while ago and a new thermostat solved the problems.

 

[nitekid]

Upgrade to an oil cooler!

Ceck for air locks.

I had the same issue when crusiing over 100MPH and my oil would reach 130 degrees when drifting etc.

I bough a 16 row oil cooler and a upgraded radiator and she is now all good

Yup, i reckon that too. A new oil cooler and a upgraded radiator will surely do the job but does not solve the roots of the problem.

 

[nitekid]

difficult one to say. have you got a water temperature gauge to compare the two? Oil temperature is closely related to water temperature. Mine tends to see a 10degree differance I would defineatly check you thermostat.

Yup, i do have a water temp and you are right, the difference was about 10degreeC. Thanks, i will look into the thermostat.

 

[nitekid]

I was thinking thermostat too. It may not be opening fully - I had this exact problem on a different car a while ago and a new thermostat solved the problems.

Oh, you had the problem before? Your Oil temp rises but water temp stable? Thanks, will get a new thermostat and hopefully it will solve the problem. Glad, i saw all your advices quick, i almost commited into a new radiator Fan, will now focus on changing the thermostat 1st instead. Thanks )

 

[craig8585]

Thermostats are dirt cheap so even if it isn't that, then there's no real loss. It's not a bad idea to change them every so often as they can wear out internally when the wax escapes.

 

[JaseYpk]

on the topic of thermostats (so not really hijacking) whats the difference between a nissan stock one and for example a GReddy one? i spotted them the other day
differences, and useability in normal driving conditions? cheers

 

[craig8585]

The aftermarket ones open at a lower temp. Bad thing in a daily driver.

 

[TurboAL]

The aftermarket ones open at a lower temp. Bad thing in a daily driver.

Yep couldn't agree more, why would you want the engine cooling water system to start cooling the engine before the oil e.t.c has come up to temperature. For race use i could see why but then you would ditch the thermostat all together.

 

[JaseYpk]

The aftermarket ones open at a lower temp. Bad thing in a daily driver.

cheers!