Overheating Issue

[YanMinor]

Hi YW,

I own a 2007 Hatchback Yaris, and I have been having a problem with the engine overheating. After driving for more than five minutes, the engine temp indicator light comes on. Also, winter in coming here in Colorado, and my heater has stopped working as well. Is there a connection between the two? I searched the forums briefly, to no avail. I think it might be either the coolant, radiator fluid, or the thermometer, but I'm having a bit of trouble figuring it out. :iono: Any help would be greatly appreciated.:help:

THANKS!!!

[CTScott]

Have you checked your coolant level? The heater runs off of the radiator fluid, so overheating plus no heat is definitely connected.

[Klink10]

Might think about a themostat also.

[Bluevitz-rs]

^The thermostat wouldn't affect the heater, the heater bypasses it.

Have a look on the underside of your hood for a pinkish spray line directly above the belts. If there is one, your water pump is shot and you're loosing the coolant through that. For now, top it up and monitor the level. Make sure you top up the rad AND the overflow container to the MAX level. If the coolant is low enough you'll need to idle the motor from cold and top it up.

DO NOT open the rad when it's hot. You can be scolded with hot steam or coolant.

[MickZEL]

Clogged radiator also affects the motor overheating.
You can remove the bumper and honeycomb radiator flush.

[YanMinor]

Thanks everyone! When I looked this morning, the coolant level was below the low-line. I'm definitely going to check everything else when I get off today. Thanks again for the help!

[CTScott]

Thanks everyone! When I looked this morning, the coolant level was below the low-line. I'm definitely going to check everything else when I get off today. Thanks again for the help!

That's the overfill tank. Open the radiator cap under the hood and add to there first. If you are at work and are going to drive home, fill it first (even if you just top it with water for now). Engines like ours don't do well with overheating.

Remove the "radiator" cap, fill it all the way, start the engine and let it run until the radiator fan starts. In the meantime, watch the open cap area, and keep adding as the air bubbles out and it goes down. Once the radiator fan starts to run, you know that thermostat is open, so let it run for a few more minutes and keep topping it. The whole process might take 15 minutes, but it is well worth the time for preventing cooking your engine.

[YanMinor]

I looked behind the overfill tank and there is definitely pink spray on some hoses down there.... Did I spring a leak?

Also, I'm having trouble getting the radiator cap off.... It twists about a quarter of a turn, but then wont lift off. Just to clarify, is it just coolant that goes in the radiator? Should I do 1/2 coolant and 1/2 water, as some have suggested?

Sorry for all the noobie questions :p

[Bluevitz-rs]

Push down and turn to get the cap off. And where is the pink coolant? Pan you take a picture?

[YanMinor]

I will try y best when I get home. The coolant has sprayed towards the rear directly behind the overfill tank. The spray seems to originate somewhere from the bottom of the tank, not the top. There is a large black hose, maybe 1.5 to 2' in diameter that the fluid has sprayed on to.

[CTScott]

I looked behind the overfill tank and there is definitely pink spray on some hoses down there.... Did I spring a leak?

Also, I'm having trouble getting the radiator cap off.... It twists about a quarter of a turn, but then wont lift off. Just to clarify, is it just coolant that goes in the radiator? Should I do 1/2 coolant and 1/2 water, as some have suggested?

Sorry for all the noobie questions :p

1/2 and 1/2 is about right if you have radiator fluid on hand. If not, straight water is better than air for now. Ideally you use a hygrometer to measure the specific gravity of your fluid and adjust the mix based on your low and high temps.

[YanMinor]

1/2 and 1/2 is about right if you have radiator fluid on hand. If not, straight water is better than air for now. Ideally you use a hygrometer to measure the specific gravity of your fluid and adjust the mix based on your low and high temps.

I'm going to go ahead and stick to the first two sentences of that post... :laugh:

[Bluevitz-rs]

Yeah if it's really leaking have a look when you get home when it's hot. You might see it pissing out a tiny pin hole.

And just an FYI. Coolant can be deadly if ingested so if you spill any try and rinse it with plenty of water or soak it up with a rag or kitty litter.

[Klink10]

^The thermostat wouldn't affect the heater, the heater bypasses it.

Have a look on the underside of your hood for a pinkish spray line directly above the belts. If there is one, your water pump is shot and you're loosing the coolant through that. For now, top it up and monitor the level. Make sure you top up the rad AND the overflow container to the MAX level. If the coolant is low enough you'll need to idle the motor from cold and top it up.

DO NOT open the rad when it's hot. You can be scolded with hot steam or coolant.

Yea but a stuck closed thermostat would have issue with running a bit hot. It was just a thought on my part.

[YanMinor]

So, this was the temporary solution I did last night. I opened the radiator filler cap and drained the radiator. I then filled the radiator to capacity with tap water and ran the engine for ten minutes. After the car cooled down, I drained the radiator in the same fashion, and added 50% water-diluted coolant, again to capacity. Then, I ran the engine for another ten minutes with the heater turned on, and refilled the coolant as necessary. The car has stopped overheating, and the heater is working (praise the Yaris gods). So thanks everyone for all of your help.

The problem still remains as to why there is pink spray under the hood. I didn't see any leaks or drips as I was flushing the radiator, so it's pretty bizarre. Hopefully the image below is clear enough to tell...?

http://imageshack.us/photo/my-images/37/wp000110.jpg/

[CTScott]

That almost looks more like spray from the radiator cap during overheating than like the typical water pump spray line. If you look at the hood is there a defined stripe of red on the inside of it?

[YanMinor]

No, there is no line on the underside of the hood, at all.

Is it typical that I would need a radiator fluid top-up this soon? My car is a 2007, and barely has 31k on it, so it seems a little early....

[CTScott]

No, there is no line on the underside of the hood, at all.

Is it typical that I would need a radiator fluid top-up this soon? My car is a 2007, and barely has 31k on it, so it seems a little early....

You may have just had enough fluid evaporate or slowly leak over time that is was down low enough to not be pumped through the radiator and hence overheated. Check it frequently to see if it goes down at all.

[A-Dingo-Ate-My-Baby]

No, there is no line on the underside of the hood, at all.

Is it typical that I would need a radiator fluid top-up this soon? My car is a 2007, and barely has 31k on it, so it seems a little early....

it is early for this to happen

keep an eye on it. something leaks

[Astroman]

it is early for this to happen

keep an eye on it

+1

[CTScott]

Out of curiosity, when you were doing the purge/fill last night, did you actually see the fan run?

[YanMinor]

No, the fan never came on. I was on a document posted by etimago that said after about 10 minutes of running, the fan should start, but it never did. My initial thought was that it I just didn't wait long enough (it was pretty cold here last night, 40F). I will leave the car on after I get home tonight to see if the fan is running.

Diagnostically, what would this mean?

[A-Dingo-Ate-My-Baby]

if the fan never runs, it could mean a temp sensor is bad, and it is
allowing the system to overheat and boil off some fluid

[CTScott]

It can take quite a while to get hot enough to cycle the fan. Turning on the AC will expedite it, as the AC ECU commands the fan to run when the AC is on. That will verify that the fan works (i.e. is not bad, or has a bad fuse or relay), but it would be good to also warm it up enough to verify that the coolant temp sensor is working. A quick drive and then let it sit running helps that as well.

[YanMinor]

Interesting. The document I was reading indicated that I should have the heater on when flushing.

Also, wouldn't the boiled off fluid run into the overflow tank? Why would it be sprayed all over those hoses in the image?

[A-Dingo-Ate-My-Baby]

Interesting. The document I was reading indicated that I should have the heater on when flushing.

Also, wouldn't the boiled off fluid run into the overflow tank? Why would it be sprayed all over those hoses in the image?

overflow only handles normal ebb and flow of daily ops

if it boils it will purge out of the tank

[Klink10]

When I changed out mine due to pump failure I refilled according to service manual and mainted the constant revs until the engine heated enough to cycle the fan. Normal running temp for me is at 182-4. Fan came on at 202 along with the overheat warning light. Just for info.

Glad you got it sorted out.

[CTScott]

Interesting. The document I was reading indicated that I should have the heater on when flushing.

Also, wouldn't the boiled off fluid run into the overflow tank? Why would it be sprayed all over those hoses in the image?

Having the heater on for flushing really doesn't do anything, since the fluid always flows though the heater, regardless of the air mix knob position.

During overheating it actually helps to run the heat on full blast, since it then acts as a secondary radiator.

[Klink10]

Thanks for the info CT.

[YanMinor]

Sorry to bring up ancient history here! First off, I wanted to say thanks to everyone for all of the help last year. Winter is coming, and I'm having the same problem again; it's like deja vu.

I thought the radiator top-off fixed the problem, but I'm certain that I shouldn't have to do this yearly.... The fan still doesn't come on when I run it for several minutes, and I think that it may be problem with the thermostat or the water pump. Does either one sound more likely than the other? Are their corresponding fixes DIYable?


Thanks again for the help ahead of time!

[CTScott]

Sorry to bring up ancient history here! First off, I wanted to say thanks to everyone for all of the help last year. Winter is coming, and I'm having the same problem again; it's like deja vu.

I thought the radiator top-off fixed the problem, but I'm certain that I shouldn't have to do this yearly.... The fan still doesn't come on when I run it for several minutes, and I think that it may be problem with the thermostat or the water pump. Does either one sound more likely than the other? Are their corresponding fixes DIYable?


Thanks again for the help ahead of time!


The temp sensor for the fan is mounted to the radiator, so if the pump was not working or if the thermostat was not opening the flow through the radiator would be significantly reduced, delaying the fan from running.

If you start the car with the radiator cap off and run it for a while (holding the engine at 2000-3000 RPM for a minute will get it warm quicker). When the thermostat opens you will see the coolant flowing by, with the cap removed.

Also, once the car is warmed up, if you turn the A/C on the fan will immediately run to verify that the fan is working.

[nookandcrannycar]

1/2 and 1/2 is about right if you have radiator fluid on hand. If not, straight water is better than air for now. Ideally you use a hygrometer to measure the specific gravity of your fluid and adjust the mix based on your low and high temps.

:bow:

[Eli Lilly]

I thought the radiator top-off fixed the problem, but I'm certain that I shouldn't have to do this yearly.... The fan still doesn't come on when I run it for several minutes, and I think that it may be problem with the thermostat or the water pump. Does either one sound more likely than the other? Are their corresponding fixes DIYable?
!

I'd guess the thermostat before the water pump. Water pumps usually leak as their failure mode, the only way they quit pumping without having eaten the serpentine belt would be for the vanes to get eaten away, which is very, very, very uncommon with modern engine coolant.

-E

[Denzel_m]

Thanks everyone! When I looked this morning, the coolant level was below the low-line. I'm definitely going to check everything else when I get off today. Thanks again for the help!

Mine is half empty/full but I've got the same problem. Can anyone help?

[CTScott]

Mine is half empty/full but I've got the same problem. Can anyone help?

Check my post #31 above and try that to see if the thermostat is actually opening.

[Denzel_m]

Check my post #31 above and try that to see if the thermostat is actually opening.

Thanks, I did that. The fan turned on. But when I put the tip of my finger in the coolant it was warm with in minutes. Is that good?

[CTScott]

Thanks, I did that. The fan turned on. But when I put the tip of my finger in the coolant it was warm with in minutes. Is that good?

That is normal. The coolant will get up to 180F within just a couple of minutes of running under load.

[Arod0610]

So I just changed the water pump radiator and thermostat and I’m still having overheating problems ... and tips or help I can get is appreciated!!

[tmontague]

Define overheating - what are you experiencing? Could be a bad rad cap, could be a faulty coolant temp sensor, could be a blown head gasket etc etc

[Arod0610]

I can drive the car for about 15-20 minutes before it goes hot also when the ac is on it goes hot faster

[06YarisRS]

So I just changed the water pump radiator and thermostat and I’m still having overheating problems ... and tips or help I can get is appreciated!!

Are you positive you put enough coolant in the car? You might have an airlock. I've done many coolant changes and the Yaris purges air pretty easily if you have enough coolant in the system. If you have a smart phone you can pick up Torque Pro app and a cheap OBD2 bluetooth adapter (everything for under $20.00) and monitor coolant temps. That's what I use so as I approach ~180 F, I start feeling the upper rad hose for heat to see that the thermostat is opening.

[Arod0610]

yeah I’m positive it has enough coolant... just today the coolant was spilling threw the resivor tank

[stykerdk]

And the electric fan is running, it should run when the AC is on.
And on mine 2013 the rpm on the fan increases when the coolant get hot.
So it could be the thermoswitch on the coolant.

[Bluevitz-rs]

Pull the rad cap while cold, start the engine and let it heat up. If start seeing bubbles you have a head gasket leak. Had that happen on an old CRX race car I used to crew for.

[Arod0610]

I tried the rad cap all I get is a couple air bubbles... could it be a bad thermostat?

[hw6515]

If everything started when you ran the car with low coolant level I think air could be the problem.

Double check all your work and flush the whole system as instructed in the water pump replacement guide.

Properly fill and bleed the air out of the system, use toyota coolant.

[Arod0610]

Got it... thanks for all the help really appreciate it