What should oil temp be?

[whiteoaks7]

The question's in the title; 100C? more? less?

 

[sailorman]

The question's in the title; 100C? more? less?

same as water temp

 

[colind3782]

At least 80c or the moisture that is produced by the combustion won't be "boiled" off and will lead to camshaft corrosion eventually.

Colin

 

[theoldsalt]

I think that the oil temperature will depend on whether the engine is direct or indirect cooled as the water temperature in an indirect cooled engine is usually much higher than a direct cooled engine. And yes I agree with Sailorman; approximately the same as the water.

 

[shaxi]

oil always hotter !may be this will help http://van.physics.illinois.edu/qa/listing.php?id=1428

 

[Cariadco]

Temps.

In Car engines, the water is at 85 to 90 degs C, dependant on the exact type of Thermostat, however the Oil temp runs a little higher, at anywhere between 100 to 120 degs C.
On a Boat diesel engine, although I dont know the exact figure, I'd expect the oil temp to be a little lower, say between 90 to 110 Degs. This would be due to the constant (and comparitivly low) RPM's that boat engines tend to run at for fairly long periods of time.

Regards.

 

[theoldsalt]

Shaxi,

Yes oil will get hotter than water for the same heat input but does the oil in the engine receive enough heat to achieve this, and what of the cooling effect of the sump?

 

[vyv_cox]

Somewhere around 90C is about right for automotive engines. Top grade synthetic oils are good for about 150C maximum, whereas minerals will begin to crack at somewhere around 110 - 120 C.

 

[prv]

water temperature in an indirect cooled engine is usually much higher than a direct cooled engine

Yep - mine's raw-water cooled, and 55º rings a bell as the proper water temperature.

Pete

 

[David2452]

Mine has always lagged behind the coolant temp by about 2 or 3 deg (digital readout) until the lump reaches a stable temperature and then the oil overtakes it by a few degrees.

 

[Heckler]

In Car engines, the water is at 85 to 90 degs C, dependant on the exact type of Thermostat, however the Oil temp runs a little higher, at anywhere between 100 to 120 degs C.
On a Boat diesel engine, although I dont know the exact figure, I'd expect the oil temp to be a little lower, say between 90 to 110 Degs. This would be due to the constant (and comparitivly low) RPM's that boat engines tend to run at for fairly long periods of time.

Regards.

+1
Stu

 

[Skylark]

Whatever oil temp the engine is designed to run at, it will always be a "temperature rise above ambient" and hence an absolute number doesn't mean too much.

Depending upon the spec of the oil, it's usually happy to about 120 deg C (generally higher for synthetics). If it's going to reach these temperatures within a normal working condition, it's likely to have a heat exchanger fitted to bring it down.

In a 20 deg C ambient, an engine oil temp around 100 deg C sounds reasonable.