1st gen. Coolant Temp. Sensor Help!

Hey guys my check engine light has been on for some time and I found out its a bad coolant temp sensor. I did some research but I couldn't find where its located on the truck! Has anyone replaced this sensor before? Its an 03' Prerunner 2.7l

 

Anyone?

 

Let me see if I have my book with me? Can you stay logged on for about 10 more min?

 

On the 2.7 it is on the same manifold that the top radiator hose comes from on the engine block.

 

I believe there are 2 coolant temp sensors for the 3RZ:

The one for the gauges (water temp sender) is the one that is located near the water inlet into the top of the engine.
The other (engine coolant temp sensor) is for the ECU, and is located on the back of the cylinder head (pain to get at).

 

Sorry about that WileECoyote. I missed your post. I posted this thread late at night and went to bed lol

 

Thanks Speedytech7! I will check it out tomorrow and see if I find it

 

You're welcome, but I think @tan4x4 is correct and that sensor is just the one for the gauge. I think the other one for the computer is on the pack of the head, shouldn't be to hard to locate as all temp sensors look pretty similar.

 

Thanks for the info tan 4x4! So I went to the auto parts store and bought a new coolant temp sensor. This is what they gave me. Im thinking this is the one that goes in the back of the cylinder head.

 

Sounds good man thanks. I'm going to try and replace it within the next couple of days. That check engine light is buggin me lol

 

Dont mean to nit pick your post here but for everyones info the 2.7l top coolant hose/port is the outlet. Inlet is the bottom hose. Backasswards of the norm, typical toyota move, haha

 

I don't if I'll help or screw you up. I have a bad sensor on my 2003 3.4. Waiting for part to come in. I have a bad "gauge" sender. It didn't trip any lights. Just makes the gauge read wrong intermittantly. The other sender, for the engine management, tripped the light when I disconnected it.

 

I believe you are right , thanx for the correction.

 

It had me baffled a couple years ago. I was having a lil overheating issue and couldnt figure out why my bottom hose was so cool while the top was scorching hot. Well, figured out thats the way it was supposed to be, haha.

Kinda curious to know if the 3.4 is the same way? Just picked up a '01 runner with the v6, i could go out and grab the hoses i guess but, what say you long time 3.4 owners? They flow backasswards too??

 

Why yes, yes it is.

 

It is on the very back of the Cylinder Head. It is a PITA to get to with the engine installed. The other sensor (single pin) is indeed in the water outlet pipe on Passenger Side Cylinder head and hose connects to the top inlet of the radiator. Sorry for the picture being off-centered. It was taken of the coolant lines/Intake side as I put the harness back on before dropping in the truck.

 

Thanks for the pic man! This helps! Would it be easier to get to it from the top or bottom of the engine since its soo close to the firewall?

 

Going from the bottom would be quite the chore im sure...

 

Top passenger side is your only option if you don't want to pull the head. Definitely remove/move both of the heater core hoses to give you some space. you could remove the wiring harness from the cab and lay it on the block as well, but it probably isn't necessary.

 

Great, thanks man!