Engine Heat Temp light comes on after radiator flush

[southpaw]

Hello Yaris world,

We just got used a 2007 Yaris with 88k miles and have an engine heat temp light that keeps coming on after driving a short distance or idling for a short period of time.

It ran fine until today when we decided to change the engine oil to full synthetic and flush the coolant in radiator. We changed the coolant because it didnt look like there was any in there, so we flushed it and added supertech 50 50 coolant and pre mixed with water. I know the manual recommends Toyota specific coolant but all the manufacturers do that and I never had any problems with vehicles in the past.

Do I need to flush the coolant and get toyota specific coolant? Could the thermostat be stuck or have gone bad during the coolant change? Any ideas what else it could be?

Thanks in advance for your help.

EDIT = Just pulled the thermostat out and tested it in boiling water and it opens up. Pull the stat out and run under cold water and it closes. Kind of points me towards toyota proprietary coolant being the issue. Any confirmation on this?

[Bluevitz-rs]

Did you make sure to bleed the system of air?

[miiser]

Hello Yaris world,

We just got used a 2007 Yaris with 88k miles and have an engine heat temp light that keeps coming on after driving a short distance or idling for a short period of time.

It ran fine until today when we decided to change the engine oil to full synthetic and flush the coolant in radiator. We changed the coolant because it didnt look like there was any in there, so we flushed it and added supertech 50 50 coolant and pre mixed with water. I know the manual recommends Toyota specific coolant but all the manufacturers do that and I never had any problems with vehicles in the past.

Do I need to flush the coolant and get toyota specific coolant? Could the thermostat be stuck or have gone bad during the coolant change? Any ideas what else it could be?

Thanks in advance for your help.

EDIT = Just pulled the thermostat out and tested it in boiling water and it opens up. Pull the stat out and run under cold water and it closes. Kind of points me towards toyota proprietary coolant being the issue. Any confirmation on this?



Maybe after you filled your radiator air got trapped in. That's the most common problem on overheating after the flush


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[southpaw]

Never heard of bleeding air out of coolant system. How would I do this?

[miiser]

Never heard of bleeding air out of coolant system. How would I do this?



Then how you did successfull flushes in the past? :p
It's so basic thing to know.
Anyways mate that's the problem. The air that got trapped in
https://youtu.be/nThsFGa1vuE

There are many tutorials on YouTube. You can check them out if this one doesn't work for you.


Here is chrisfx one of the most famous diy guru : (10:30 is the air bleed method)
https://youtu.be/s--5ft5YiHg


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[dogsridewith]

some cars don't need fussy bleeding...just add coolant as level(s) drop. some cars owners suggest you drill a 1/8" hole in the thermostat

[Bluevitz-rs]

It's pretty easy. First make sure you have coolant in the overfill tank. Then fill the rad up to the top. Then place your palm over the fill hole and squeeze the upper rad hose like a pump. You'll feel the bubbles push out and into the overfill tank. It also help to raise the left side of the car with a jack or you can drive it up on a curb to help the bubbles want to slide out. Also make sure the heater is cranked all the way over to Hot so air doesn't get trapped in there. When you are done and don't feel any more bubbles, you can start the car and then go hold your hand over the opening of the radiator again. Continue using the upper radiator hose like a pump. Once your feel no more bubbles in the radiator starts getting hot, you'll know the thermostat is opening. The system should be blead now

[dogsridewith]

Thought I read somewhere that Yaris doesn't have a "water valve" in the heater system?

[bairjo]

Do a search for Coolant flush procedure in yarisworld....it was brought up about 3 or 4 years ago....

[SirDigby]

there is also a valve on the back of the block near the exhaust manifold. you need to bleed that too...