Oil temp gauge - under-reading?

[TeaMonsta]

The engine oil temperature gauge in my Surf takes ages to indicate and when it does, it sits about 40% up from the bottom of the gauge (if 0% is bottom of the cold band and 100% is top of the hot band). I've also noticed that when I'm stationary for a while, the temperature indicates as being cool (just above the cold band). Surely, once the engine is up to temperature, it should remain more or less around that temperature whilst the engine is running?

[muddle]

You sure its not oil pressure

[TeaMonsta]

I haven't got a pressure gauge installed but I'm thinking that low oil pressure would give a high temperature. The oil light hasn't come on, not even briefly (apart from when it lights up when you first turn the ignition key). High oil pressure wouldn't have too much effect on temperature, would it? I don't know, I'm certainly no mechanic!

[TonyN]

Is this an aftermarket guage? Surfs don't have a oil temp guage, just coolant temp.

[muddle]

Im sure its a pressure guage, think you have gotten mixed up, post or find a pic of it

[TonyN]

Im sure its a pressure guage, think you have gotten mixed up, post or find a pic of it

3rd Gens only have temp and fuel gauge on cluster, no oil press or amps like 2nd Gens, that why I asked about the guage.

[TeaMonsta]

The gauge I'm referring to is located to the far left of the instrument panel (left of the rev counter). It has a symbol on it similar to the one shown here (although it's not red):

[BUSHWHACKER]

The gauge I'm referring to is located to the far left of the instrument panel (left of the rev counter). It has a symbol on it similar to the one shown here (although it's not red):

Coolant temp gauge.

A thermometer being dipped into water?

[TeaMonsta]

So it's the temperature of the fluid in the radiator, then? That could explain why the temperature reading is lower when the car's at a stand-still; lower revs, therefore less heat. But at a stand-still the radiator's getting no cooling airflow over it, which would make the engine run hotter, perhaps. Are the indications I'm getting as described above in my first post correct? Does the temperature indication normally fluctuate in Surfs?

[BUSHWHACKER]

If the engine is just idling, then the temp gauge will drop slightly as the viscous fan will be pulling enough air through the radiator.
As soon as you start driving, more heat is generated within the engine and the temp gauge will move accordingly.

If the temp gauge is fluctuating when you're cruising , then the thermostat is not working properly.

Practically all Toyota temperature gauges of the same era are not very accurate, fit an after market gauge to work alongside the factory gauge and you'll see the difference in readings.

[TeaMonsta]

That's great, thanks BushWhacker. Seems like everything's ok, then. My concern, really, was that it wouldn't tell me if the engine was about to overheat but from what you're saying it should all be fine. Thanks again.

[NiftyNev]

My concern, really, was that it wouldn't tell me if the engine was about to overheat but from what you're saying it should all be fine. Thanks again.

The factory gauge will let you know when it overheats. It's just that it will do it when it's too late. The gauges operate this way. Cold, normal and Oh Sh!t!

Nev

[Wolfracer]

my guage looks like this:

[TeaMonsta]

my guage looks like this:

Where can I get one?