Water temp/coolant/thermostat sensor replacement

Hi there, just bought a 1995 1kz-te. After changing the fuel filter I noticed the fan came as soon as I turn the key before the ignition. On closer inspection I see this little sensor is damaged and google gives me all kinds of names for it.



I’ve gotten a replacement and the bolt the broken piece on is threaded. My question is: is it okay to replace this myself? Do I need to do anything special other than remove broken piece and replace new piece?

Coinciding with me noticing this extra fan use and broken sensor is a new noise behind the dash. A ticking noise that sounds like a fan but after taking the dash apart. I’ve noticed that when the sensor is disconnected the ticking noise happens but when I jam the sensor back into the bolt that holds it, the noise subsides until it’s knocked loose. Will replacing the sensor stop the ticking? Do I need to replace this relay too?

I can’t quite figure out how to attach photos and videos. Uploading and hosting from Flickr doesn’t work but here is a link to a part that looks similar to the one I ordered from repco. The one I received is 17mm

https://shop.thepartsman.com.au/product/toyota-hiace-200-series-1-05-2-19-water-temp-sensor-2-7l-2tr-fe-4cyl-petrol/?gad_source=1&gclid=CjwKCAiAx_GqBhBQEiwAlDNAZrwROHctiodZs87C-UcYmETJ56pCd0Pm0aQb2wz9kvPIDxFYPF2gJBoCaDIQAvD_BwE


Thank you

Hello Moonroofed (like it!) and welcome to the forum.

Attaching pictures is a bit clunky. I think the option to allow you to add pictures comes after you’ve made a few posts? This might help:

https://hiace-super-custom.forumotion.com/t12-how-to-upload-a-picture


It might be you have an aftermarket radiator fan system. My van, like many similar-aged Toyotas has the oil-filled fan clutch that was fitted to Landcruiser, Hilux etc. This OEM system is not electrically operated. Have a look on the Timmy the Toolman YT vid here:



I realise this if your setup is different this may not help, but it might help you determine if you have an original or modified system.

I don’t think there’s anything necessarily wrong with adding or moving to an electric fan, as long as you have the oomph to run it and you have the best cooling system you can get. I don’t have the 1kz-te engine, but I understand this needs tip-top cooling.

Sorry, I can’t help you with your clicking etc, but you might like to take a look at the first post in my Show Us Yours! section (click home then scroll down to ‘Pictures of your Hiace’ and look in there for my username. The first post includes lots of links and other resources that I hope might help. There’s also another longish post on the first page on cooling. This starts after the pictures of the rear drums there. Again hope this helps, though I acknowledge your van is a different model.

Good luck!!

Hi - I'm wondering if the sensor is the standard temp sensor that feeds the ECU computer - or if it's a non-standard one that's been inserted somewhere else in the coolant flow? if it's the standard one that's been modified to also feed your electric fan, then that may explain the clicking behind the dash (if the ECU is trying to set solenoids etc).

All of the following assumes it's the standard sensor. When you say 'jam it in', it sounds like part of the internals of the sensor could have been pulled out and still attached to the harness plug? If that's the case and it's shorting, that may explain the fan coming on immediately? Difficult to say. if you could get photos uploaded, it may help. it's the icon with the screen and little floppy disc logo. You need to upload, select and insert into the post.

Our temp sensor was damaged the connection tab was broken of the fan ran continuously I drilled it and screwed it with a new tab it has worked for 2 years .

JT69 wrote:

Our temp sensor was damaged the connection tab was broken of the fan ran continuously I drilled it and screwed it with  a new tab it has worked for 2 years .

Ah, are the electric fans standard on some hiaces then? Is it in place of the viscous coupled one behind the main radiator?

The electric fan is in addition to the viscous fan normally comes on at high temp also some come on when air con is switched on .

JT69 wrote:

The electric fan is in addition to the viscous fan normally comes on at high temp also some come on when air con is switched on .  

Is it associated with the flat secondary radiator or does it work in conjunction with the main one? I'm trying to work out if it's something I can add to my van. Thanks

Here some photos of the sensor and the part behind the dash making noise

It’s the part circled that seemed to be making the noise. I took the closest one off and cleaned it a little. The noise seems to have subsided but the fan still comes on so I’m wondering can I fit the new part myself or do I need to do something

special[

Moonroofed wrote:

Here some photos of the sensor and the part behind the dash making noise

That's definitely half the sensor still stuck in the socket - there should be a little flange to push in and it should pop out. Whatever happens, you'll need a new sensor, so replace that and see what happens. That other photo looks like a solenoid of some sort. Hopefully a new sensor will fix it.

I only have hands on experience with petrol hiaces and the diesels have more temp sensors than the petrol one - so you'll need to identify which one it is. But looking at the EPC pages, I'm guessing it's: SWITCH, TEMPERATURE DETECT, NO.2 (part no. 89428-20100)

https://toyota.epc-data.com/regius_ace/kzh106w/109611/electric/8401/89428/

Is it the vertical sensor - 89428, in the first picture?

On my van this sensor is a switch that is normally closed and goes open circuit at about 95 - 100 deg C, this open circuit triggers the electric fan over the horizontal radiator to go to full speed.
It looks as if your sensor has broken in two, hence it is effectively open circuit. It screws into the underside of the water inlet elbow which can be unbolted from the cylinder head quite easily. You can test the control circuit by bridging the two wires in the connector you are holding, the fan should stop or go to slow speed if the A/C is switched on. As g00se mentions, part number 89428

We have the culprit. I fear some damage to the head gasket