Celica Forums General Discussion Engine and Performance Car keeps Overheating

Hello everyone, I'm new here on this forum but please bear with me

So I acquired my uncles old Celica GTS 2000 but we had to send it to the shop because the Clutch was shot. That was the only problem with the car. Once the mechanic said we could pick up the car, we went and finally took it home. But on the way there the car started to overheat which was a new problem which never happened before as well as the air system doesn't function (other than blowing outside temp air). Its been about a year and a half since that happened and me and my grandfather who used to be a mechanic have gone through tons of troubleshooting which include changing the thermostat, water pump, radiator and cleaning all of the pipes to make sure that they aren't clogged. But none of them worked but we've come to the conclusion that its all because the thermostat doesn't open. So if anyone has any solutions, I'm all ears.

Extra info is that the car tends to overheat while idling after around 15 minutes and even less if you try to drive it

I had this problem with mine b4. I put a new thermo in, replaced all my coolant hoses, and flushed the system. You might need to put the coolant under pressure to get any bubbles out. Since the Celica so low to the ground, the coolant can't flow normally (down). It took me a few weeks and even then I ended up taking it to the dealer so they could pressure pump the coolant in (took them 3 tries). Best of luck to you.

Edit: I just remembered. I also unhooked the reservoir and held it up above the car while I poured the coolant in. That seemed to help, even though I still needed the pressure. Try that b4 you take it to anywhere expensive.

Thank you. I will try that but I do you know if there's any other way to get the pressure done? And how much did it cost for you to get it done?

Is the overheating transient or steady?

If overheating is transient with spikes then goes away, and heater blows only cool air, it looks like coolant was not bled properly and there is a large air block trapped in the cooling system.

If overheating is long and steady while driving then it's likely calcium deposits are blocking the coolant tubes somewhere in the engine or radiator. Thsi is a very serious problem that can crack your engine. Don't drive the car until you fix it. You may want to add calcium dissolving chemicals in the coolant and follow instructions to flush the system clean before refilling and rebleeding. Try to bleed out that air block by following the bleeding instructions on a label under the hood.

Basically after draining coolant, raise the coolant reservoir and stick it on the hood's hook. Add about 4 quarts of 50/50 coolant in the reservoir which flows down into the engine block. Idle the engine to operating temp. Keep the reservoir level to high and keep adding coolant ( up to 4 quarts) as the thermostat opens and sucks coolant in. Don't let it suck in air, just more to bleed later. Coolant pump would start driving coolant through engine out to radiator, expelling any air inside. Keep watching the reservoir and add coolant to high level. When radiator fans turn on and run the second time, most air would have been driven out, the bleeding is mostly done. Cap the reservoir and put it back in its place.

Watch coolant level in the reservoir and add coolant if low. Any air left in the system will be pumped into the reservoir. Uncapping it will release residual air out.


https://workshop-manuals.com/toyota/celica_gt-s/l4-1.8l_(2zz-ge)/engine_cooling_and_exhaust/cooling_system/coolant/component_information/specifications/page_1549/#:~:text=Supply%20coolant%20of%20approx.,the%20level%20reaches%20FULL%20line.&text=Use%20of%20improper%20coolants%20may%20damage%20engine%20cooling%20system.

It just sounds like you didnt bleed the system fully. It's extremely tricky and requires one mount the coolant reservoir onto the hood latch so as to elevate it above the engine and give the bubbles somewhere to go. You might even need to jack the front up to further facilitate that action. Then you need to alternate between holding the revs at 3000 for 10 seconds and letting it idle for 10 seconds. Toyota says do this for at least 15 minutes, but chances are you'll need to do it for almost 30, then test drive and check for overheating. It also helps to have your heat on full blast to allow the coolant to get to the heat core easier, further removing trapped air.

Hi Action Seeker,

I appreciate your concerns but this bleeding procedure is not difficult. I have multiple GTS and have done it successfully dozen times.

If you jack up the front end, the radiator will be way higher than the head than necessary, you will be overfilling the system with coolant. Toyota's engineers designed Celica's cooling system to be bled level on the ground.

1. Leave the car level on the ground, cabin heater off, drain the radiator then close it (I don't open the butterfly ballcock at radiator's bottom, but open the 2- inch return hose on passenger side, easier and quicker). if coolant looks dirty or rusty, flush radiator with calcium dissolving chemicals and distilled water .

2. Remove 2x 1/4 inch black rubber hoses on reservoir. Raise and pluck reservoir on hood hook, add about 4 quarts coolant to flow into the block and out to radiator. If car is level, radiator should be about full and fluid with air bubbles will start coming out of the 1/4 inch rubber hose.

3. Put reservoir back to its place, plug back the 2 1/4 inch rubber hoses, cap off and butterfly cap open.

4. Keep adding coolant into reservoir up to max hot full level. Alternate idling and revving to 3000 RPM every 15 seconds to heat engine up to op temp. Thermostat should open and coolant pumped into the block, sucking in coolant from reservoir, so keep adding coolant to max hot full to prevent air pockets sucked in and require longer bleeding. It will suck in about 1/3 gallon coolant more to fill up.

5. Hot coolant and hot air should be squirting into the reservoir's chambers from radiator via the 2x 1/4 inch hoses out the butterfly hole. Keep adding coolant to hi hot level; and wait for cooling fans to turn on then off twice. At that point coolant had circulate through engine and radiator a few times and most air bubbles had been pumped out. Cap off the reservoir and butterfly. There is enough coolant in engine such that it is safe. Next couple days monitor and add coolant in reservoir if low. Any small pockets of air would be driven out into the reservoir and puff out when you uncap.

6. If engine temp gauge shows overheat spikes, don't worry about it. They are just super-heated air pockets driven past the temp sensor. The rest of the engine still has close to 4 gallons of coolant and will not over heat. Turn off engine and restart, it would go away. Any air pockets will be driven out to the reservoir. When you uncap they will puff out.

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