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Quick question: Where's the Coolant Temp Sensor?

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1996 Legacy, 2.2L. The Haynes manual says it's on the coolant pipe by the upper radiator hose, but I can't find it anywhere.

 

The car won't start when cold. Plus, my Check Engine Light's been on for a month, saying I need a new C.T.S. I'm hoping to locate the sensor so I can unplug it until I get around to replacing it.

 

Thanks.

I believe the coolant temp sensor you are looking for is located under the intake manifold on the coolant passage/pipe that connects to the upper radiator hose. You will have to look behind & below the intake manifold to find it.Should be visible from the back side.

Hi and welcome! '96 Legacy 2.2L here too. Same issue last year. The sensor is a little tricky to see from the top of the engine. It's basically underneath one of the intake manifold pipes, sort of near the IACV. A good assortment of flex sockets, adapters, etc, makes the job easier.

  • Author

Hi, Porcupine! I'm in Buffalo, as well. Actually, I'm only a few miles from UB, so I ride the bike to school and only put about 200 miles on the car in a month.

 

I've located the IACV, PCV port on the passenger's head, the coolant pipe, and something bolted to the manifold runner that I think is part of the evap system. I'll keep looking.

 

I ordered the part, so it'll arrive on Wednesday. If I can't find it then, I'll start removing nearby parts until I see it.

Welcome BobSmalls! Wow that's interesting, my last name is Small. My '96 brighton is an auto. When I replaced that sensor, I think I pulled out all that plastic air intake stuff and some of those hoses around it, especially the hoses from PCV valve down to the block and to the bottom of the plastic air intake.

 

Then if you look underneath that intake manifold pipe, you should see two sensors right next to each other. The one closer to the driver side (LH) is the ECTS. The one closer to the passenger side (RH) is the coolant temp sensor for the gauge. The ECTS uses like a copper sealing washer (not teflon tape or anything like that).

 

Maybe later today I'll see if I can get pic.

OK BobSmalls, here's a pic of the ECTS (engine coolant temp sensor) from my '96 Legacy Brighton: It's very near and below the PCV valve: (This is not the sensor that feeds the temp gauge).

ects1a.jpg

 

Here it is, a little easier to see, on my '94 Legacy; it's the brownish colored item in the center of the pic:

ects3.jpg

  • Author

Awesome. Thanks, Porcupine! Mine is under a knot of wires, a mass of plastic wire armor, and a wad of electrical tape.

 

What a pain that was for such a simple job. My PCV hoses are probably the original ones, and they're rock-hard. I probably should have changed them, but whatever. And I'd like to slap the engineer who chose those squeeze-type hose clamps over normal worm-gear hose clamps.

 

Once I removed the PCV system, it took me thirty seconds to change the sensor. It naturally leaked a bit of coolant onto my engine, so I did pour 5 gal of water all over the top of the engine. Heh. It didn't run too well until that dried.

 

But it's all sorted out now. I love my 'ru again, for now.

Alright good job! Yah I forgot about the coolant coming out. You might want to check the radiator bleeder screw thing at the top of the radiator RH (passeng.) side. You don't want to get any air pockets trapped in the cooling system.

 

Sounds like maybe it's time for plug wires or coil pack inspection if the water mad it run poorly?

  • Author

Yeah, it sure sounds like it. :-P

 

I drive the car 2000 miles a year. I don't need it to run well. I just need it to run.

 

The CTS was covered in a mm-thick yellow-brown paste. I'll do a flush and fill tomorrow, complete with a bottle of Coolant Flush. Then we'll see about air bubbles.

  • 7 months later...
OK BobSmalls, here's a pic of the ECTS (engine coolant temp sensor) from my '96 Legacy Brighton: It's very near and below the PCV valve: (This is not the sensor that feeds the temp gauge).

ects1a.jpg

 

Here it is, a little easier to see, on my '94 Legacy; it's the brownish colored item in the center of the pic:

ects3.jpg

 

Blowing the dust off an old thread....

 

 

So is there a different sensor for the temp gauge? mine don't work very well.

 

When my 96 Legacy Outback 2.2 wagon is warmed up, the gauge is just a tiny bit above the cool line.:eek:

Yes, the coolant temp sensor (CTS) for the temp gauge is a different sensor from the engine coolant temp sensor (ECTS). The CTS is located right next to the ECTS though.

Yes, it's the one on the pass side with only one wire going to it and it has a simple slide on blade connector that can more easily oxidize. Check the connection before doing anything else.

Yes, it's the one on the pass side with only one wire going to it and it has a simple slide on blade connector that can more easily oxidize. Check the connection before doing anything else.

 

Thank you both, I will look for it this weekend:banana:

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