Celica Forums General Discussion Engine and Performance Overheating

Ive got a 2000 vvti 140, only done around 94k miles, recently
It started overheating, i checked and my
Coolants needed topped up, i done so and after around 10-15mins it had started overheating & once engine cooled down i checked and had went down from just over full to the low mark,
A quick drive home caused the same problem, with engine management light on.

So today i stuck a 250ml bottle of radweld through it, topping up with Coolant. Ran it idle
For 30minutes , temperature gauge worked upto the middle and stayed steady the duration.
I inspected under the car and under the radiator their seemed to be a tiny water mark, but inspectingb the coolant bottle & nothing had left it.

10 minutes into driving into work it began flashing at the overheating mark again. Ive not checked coolant levels, waiting until
Engine cools down, but there doesnt seem to be any leak lines behind car? As i had saw previous night to adding radweld?

Anyone got any suggestions?
If the coolants fine after the engines
Cooled down would
It just be the temperature gauge? Or can it still be the heater matrix or radiator?

the water mark left on the ground or around your engine components is probably condensation/moisture, that could come from your A/C. That is normal - most cars do it.

Your radiator fluid should be checked when your car is cool. Not hot. The overflow reservoir will give the most accurate reading when it's cool and it's nearly full.

You've probably already had a quick read through this section, but if not, review item #2 "FILL ENGINE COOLANT" section.
https://celicahobby.com/forums/ubbt...ct-replace-or-drain-fill.html#Post296224

Coming from a very low/to none coolant level, the anti-freeze filling requires a gravity-type of system to fill. The instructions for that are outlines in the link.

A few other ideas of things to look at, on top of the anti-freeze fluid level/correct fluid type, is the temperature gauge functioning correctly (which you mentioned above). When it's HOT, it will be near or just above 195F, and will display as mid/upper-mid level on your dash/gauge cluster for that temp. The radiator fan should engage at about 199F.

If you have an ODBII reader, you can pull the codes that your vehicle is throwing. Or if you have an ODBII Bluetooth dongle, you could monitor the temperatures with your Smartphone or Laptop (I use the "Torque" app with a custom plug-in on Android) which your Celica's computer system (ECU) believes your engine is running at, in real time. For example, see attached image: