Oil temperature

[MichelvdM]

Hello all,

I have an oil temperature gauge in my Spitfire where the sensor is built in the drain plug in the oil sump.
The temperature gauge is not indicating more than 70 degrees C. Is this a normal temperature?
It also takes quite some time before this temperature is reached (20+ km). I am wondering if the location of the sensor is the best.
Anyone any idea?

Thanks and regards,
Michel

[RedRooster]

Have the same in my Sprite, need to take it out for a drive to confirm the temp, it's been a while since the last drive out.
RR

[Dannyb]

It could be the sensor is not matched with the gauge, I'm thinking yours is a electric sensor and not thermal.
My sensor is also fitted to the sump plug and I'm using a water temp gauge. It took awhile to match the right sensor to the gauge. I wired mine up on the workbench and put the sensor in hot water and checked the reading on the gauge with a thermometer in the water.
You could use a lazer thermometer to check the temperature of the sump.
The oil in my sump takes a lot of miles to get up to normal temperature.

[nang]

If you're using a water temp gauge (and presumably sender) is the gauge wired through a voltage stabilizer as fitted to temp and fuel gauge ? If not gauge readings will not be accurate.
Tony.

[John Bonnett]

Mine doesn't go above 80C. It is an electrical rather than capillary instrument and they are not as accurate. But in this case it could be because the sensor is not fully introduced into the sump as a capillary would be and so it may not be seeing the oil at its actual temperature. I did send the gauge back to have its calibration checked but that made very little difference.  

[Nick Jones]

Oil temperature is very dependent on how hard the engine is working.  At idle or just pottering about at low revs it'll take a good while to come up and won't go very high, whereas a sustained high speed cruise or spirited cross-country dash will bring it up quite quickly.

This is why alot of modern cars have water/oil heat exchangers as standard fit.  These bring the oil up to temperature more quickly and then hold it steady-ish at a few degrees above the coolant temperature.  Can be retro-fitted but a fair amount of effort/plumbing involved.

Nick