So my temp gauge on the dash reads about one point up from cold during normal running conditions (ie driving at 60kmh or over).

 

In stop start traffic and only on hot days will the temp gauge make it up to the middle of the gauge. On colder days the gauge won't even read above about 1/4 in stop start traffic.

 

Is this a bad thing or a dodgy temp sensor that should be replaced?

 

Will running "cold" have any negative effect on the engine or fuel efficiency? I get 500-600 kms per tank doing roughly 50/50 city/highway driving so it seems pretty good. (7-8L/100km)

 

Thanks!

I wonder if someone has removed the thermostat.

Sounds like thermostats stuck open or missing completely

Or the temp gauge sender is all scaled up and not contacting the water right. You can wire brush it clean and reinstall.

99% guarantee it's the thermostat, either stuck open or it has been removed. Easy job on a 4AFE and worth doing regardless.

Cool thanks for the replies. It was my nannas car and grandmas before that so I doubt its been removed unless they took it to a shonky mechanic. Lol. Probably needs a radiator flush anyway looks like its just water in there.

 

If I search will I find any good tutorials on servicing/changing the thermostat and also the coolant?

Better off buying a workshop manual for you car.

~$50-60 will get you the Gregorys manual, you'll save that in labour costs on the very first home job you do, everything else is pure savings (and the Gregorys for this model is quite good compared to a lot of the others).

 

If you've ever poked a car with a spanner before then you probably wouldn't even need a manual for the thermostat change, everything is pretty much in plain sight and easy to get to.

Gregory's it is then.

 

Looked on eBay, tridon thermostats seem to come up first for $20-40. Do I need a "high flow" one?

Hit up your local dealership and find out how much a genuine Toyota thermostat is, if it's not too much more than the Tridon I'd go for that, heard some stories about the Tridons not going the distance. No need for "high-flow" _anything_ on a stock 4AFE.