Coolant temp sensor code PO115

[Chantelle]

My 2003 Toyota Echo is showing a flashing overheating light when I travel at 100kms or over 2.5grand rpms. When I lower the acceleration to 2gramd or under it immediately disappears. The warning light only comes on if you sit on 100 KMs or 3grand rpms. Although this isn't effecting use. I have traveled long distance in the car and had no mechanical issues stop my car. I have changed thermostat and coolant temperature sensor although it is still happening. Could this be a water pump?

Edited April 28, 2021 by Chantelle
Spelling

[campbeam]

I was more thinking of the radiator needing to be flushed or replaced.

[Tony Prodigy]

 

4 hours ago, Chantelle said:

My 2003 Toyota Echo is showing a flashing overheating light

What is the temperature gauge reading when you see this flashing warning ? It has a temp gauge right ?

4 hours ago, Chantelle said:

I have changed thermostat and coolant temperature sensor although it is still happening. Could this be a water pump?

If the impeller on the pump is broken and is not able to pump water around, firstly, you will know about it because it will make a horrid sound and secondly, your car will over heat very quickly in traffic. 

Also, was the coolant completely drained when the work you mentioned was carried out ? I wonder if new coolant was used or just filed up with tap water. Tap water is a big no no for modern engines as the alloy will corrode due to the mineral content of good old Sydney water. It's high hardness rate so will scale and do all sorts of nasty stuff inside your engine if used alone.

[Chantelle]

On 4/28/2021 at 1:25 PM, campbeam said:

I was more thinking of the radiator needing to be flushed or replaced.

Hi, yes I have ordered a new one and going to try flushing it. It's only a new one. I've only just brought the car but do you think it's chemy weld blocking it?

[Tony Prodigy]

4 hours ago, Chantelle said:

do you think it's chemy weld blocking it

Ok, so now your saying the radiator has had a repair ? If some kind of epoxy glue was used in the radiator core, it could be possible the flow could've been restricted, but that's a long shot. 

Also, just wondering if there is air in the system and if the Echo has a similar bleeding procedure to other Toyotas. Ashley (Campbeam) should know this one.

[campbeam]

4 hours ago, Chantelle said:

Hi, yes I have ordered a new one and going to try flushing it. It's only a new one. I've only just brought the car but do you think it's chemy weld blocking it?

Are you DIY or someone else doing the work on the vehicle? How experienced are they? Are you saying that a new radiator was recently fitted to the vehicle by the previous owner?

59 minutes ago, Tony Prodigy said:

wondering if there is air in the system

I did think about it but dismissed it thinking that when the thermostat and coolant sensor were recently replaced then the cooling system would have been burped at that time.

Good idea to check the coolant level in the reservoir. When the engine is cold, I would undo the radiator cap and confirm that the coolant level is OK otherwise top up. Repeat this check a few times. I would also drive with the heater on so the coolant circulates through the heater.

Now you have got me also thinking about checking the condition of the radiator hoses. 

https://www.wikihow.com/Check-Radiator-Hoses

 

[Chantelle]

On 4/28/2021 at 1:25 PM, campbeam said:

I was more thinking of the radiator needing to be flushed or replaced.

Previous owner replaced radiator, I replaced coolant temp sensor. I have purchased new water pump yet to be installed just incase. I always top up the coolant although it seems to use way too much. Overheating is hard to monitor as there is only two lights that show, either red flashing or green when U first start. To middle gauge. Had thermometer on all parts of engine, one side of radiator is hotter than the other. Which is what made me think previous owner chemy welded head instead of replacing. No overheating or head issues or symptoms present tho, just assuming this is causing blockage. Only overheats when rpms are at or over 3grand. Doesn't do it at all under that. 

[Chantelle]

Engine light now coming on and won't go off. Using half a bottle of coolant in 20kms although no leaks.

[Tony Prodigy]

2 hours ago, Chantelle said:

Engine light now coming on and won't go off. Using half a bottle of coolant in 20kms although no leaks.

I'm wondering if the head gasket could be going bad. A compression test can confirm this.

Also these below.

Bad head gasket symptoms

1. White smoke coming from the tailpipe.
2. BUBBLING IN THE RADIATOR AND COOLANT RESERVOIR.
3. unexplained coolant loss with no leaks.
4. Milky white coloration in the oil.
5. Engine overheating