My coolant temp gauge is bouncing all over the place so I picked up a new sender from Northridge (Thanks for the YT discount Evan!) but I can't seem to find where the darn thing is. I believe it is somewhere on the pass side of the block but I can't find it for the life of me.

 

It's on top of the block, close to the LH intake plenum and partially obscured by the plastic timing cover. Dr. Zchivago has a good pic when he's describing the ECT mod. It has a little gray connnector on it with a green and an orange wire going to the ECU. Sorry for not having pic's.

 

You mean, this one?



That's a pic of the junction for the splice to do the mod. The sensor itself is _under_ the plenum which makes it a PITA to replace.

 

Okay, I found it thanks to your description, now how the hell do I get at it to remove it? Can I remove the hardline that bridges the two fuel rails? That would give me access but I'm afraid of introducing air to the fuel system.

 

Yup that's the pic. Thanks Midiwall. Sean I've never messed with the sensor itself but I wouldn't worry about air in the fuel system. The fuel pump will purge the lines when it kicks on. It would be like cranking the engine with the pump fuse pulled or running out of fuel . It's a low pressure system compared to a diesel so I don't think it needs to be bled. Please someone correct me if I'm wrong. When you get it all back together simply cycle the key a few times before actually cranking.

 

I took the fuel line off and then of course my 19mm deep socket was about 1/8" not deep enough to grab the sender, I could grip it but barely and I didn't want to round it off. I used some pliers to crush the plastic end of the old sender so the socket could engage deeper and then I installed the new one torqued down as tight as I could get it with what little engagement I got out of the socket. Anyone replacing their sender might want to get a super deep 19mm socket before hand, I hope mine doesn't come loose that would royally suck but I was able to get it fairly snug.

 

Water temp sender is at the back of the top side of the engine. It feeds the temp gauge on the cluster. The engine coolant temperature sensor that supplies the signal to the ECU is located at the front of the top side of the engine.

 

Cool - I had 'em backwards. I deleted my previous message to avoid confusion.

 

Here's 2 good pics to show locations of various sensors:




They are labelled ECT sensor and ECT gauge sender.

 

Thanks for the diagram scan. I replaced the sensor and the gauge is still acting weird, I guess now it's time to replace the sender and possibly the gauge itself.

 

Here are a few photos of the location and exchange of the Coolant Temp Sensor on my 96 4Runner V-6



The sensor sits just behind the timing belt cover on the left if facing the engine.





You will need to remove the coolant, upper radiator hose and cover.





This is the location. It sits just under the fuel rail.





Disconnect the wire. These are fuel rails are pressurized, so just be careful NOT to yank on them when loosening. The aluminium fuel injector lines could break.





You will have to remove one bolt and loosen the other one in order to swing the fuel line out of the way.





I put shop towels under my fuel rails to catch the small amount that comes out. I used a 21mm deep impact socket on a ratchet to remove the sensor...





and a 20mm deep to install the new one.





This is the old sensor





Before removing the sensor i cleaned any excess gunk then once removed I used a swab to clean a little more making sure nothing went inside.





This is the new sensor installed and the fuel lines and wires all connected.