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can't find the right engine coolant temp sensor

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Old 08-30-2010, 07:48 PM
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can't find the right engine coolant temp sensor

I must be confused, I've been to two different parts stores and not been able to find the engine coolant temperature sensor for my truck. Its a 1992 with a 22re. The sensor I've been pulling out is below the throttle body on the front of the lower intake manifold. It is right next to another sensor with a green plug, which I thought, from research here, should be the cold start injector switch. Everytime I order the sensor from a parts store they give me one that looks very similar and uses the same plug. The probe and the threads are smaller though. Also, when I ordered plug wires, cap and rotor I had to take them back and replace them for a 1993, apparently the coil in my truck is off a 93 or it was a late model, or a swap or something? Either way the sensor they are trying to give me is for a 93-2000. Am I mistaken on the sensor I'm looking for?
Old 08-30-2010, 08:18 PM
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The coolant temp sensor that you talking located next to the thermal time switch is used by the computer to monitor the coolant temp. The temp sensor for the temp gauge on the dash is located between the valve cover and intake manifold in the middle.
Old 08-30-2010, 08:21 PM
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I have just spent the last month or so dealing with the same problem... Now, there are up to four different "coolant temperature senders / sensors / switches" or whatever you would like to call them on the 22re. After much of my own research this is what I have come up with. The two sensors you talk about under the thermostat housing are indeed what you are talking about. The one on the left is the cold start injector sensor switch. The sensor on the right is the engine temp sensor for just the ecu. There is likely, also a sender down on the passenger side of the head by the fuel rail. This is the sender for the guage, so if your guage is not working properly, this is the sender you want to replace, not the one up front. The fourth sensor is probably the most obvious and oddly enough the most obscure. It is located in the top of the thermostat housing. According to the toyota guy at the local parts store, its for the overheating idiot light, which my truck doesn't have but I do have the sensor. Some people have said that its for the fan clutch, but on a 22re, the fan clutches are all analog. The Haynes repair manual really doesn't say anything about that sensor either. It is possible that your engine is out of a 1993 truck and that they swapped all those other goodies as well. Its also very likley that you do infact have a late model 1992. The only constant with these engines is inconsistency...
Old 08-30-2010, 08:54 PM
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Originally Posted by americanmcss
I have just spent the last month or so dealing with the same problem... Now, there are up to four different "coolant temperature senders / sensors / switches" or whatever you would like to call them on the 22re. After much of my own research this is what I have come up with. The two sensors you talk about under the thermostat housing are indeed what you are talking about. The one on the left is the cold start injector sensor switch. The sensor on the right is the engine temp sensor for just the ecu. There is likely, also a sender down on the passenger side of the head by the fuel rail. This is the sender for the guage, so if your guage is not working properly, this is the sender you want to replace, not the one up front. The fourth sensor is probably the most obvious and oddly enough the most obscure. It is located in the top of the thermostat housing. According to the toyota guy at the local parts store, its for the overheating idiot light, which my truck doesn't have but I do have the sensor. Some people have said that its for the fan clutch, but on a 22re, the fan clutches are all analog. The Haynes repair manual really doesn't say anything about that sensor either. It is possible that your engine is out of a 1993 truck and that they swapped all those other goodies as well. Its also very likley that you do infact have a late model 1992. The only constant with these engines is inconsistency...
If you have a temp gauge, then the truck doesn`t have an idiot light. From what ive read the temp sender on the thermostat housing has something to do with the a/c, my 86 4Runner has this temp sensor. but if you need the temp sending unit for the gauge then its the one by the fuel rail on the intake manifold. Another thing to check if your temp gauge isn`t properly working is to pull the gauge cluster and clean and tighten the ground screws on the printed circuit board.

The guy your dealing with at the parts store is an idiot.

Last edited by myyota; 08-30-2010 at 08:55 PM.
Old 08-30-2010, 09:04 PM
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Originally Posted by myyota
If you have a temp gauge, then the truck doesn`t have an idiot light. From what ive read the temp sender on the thermostat housing has something to do with the a/c, my 86 4Runner has this temp sensor. but if you need the temp sending unit for the gauge then its the one by the fuel rail on the intake manifold. Another thing to check if your temp gauge isn`t properly working is to pull the gauge cluster and clean and tighten the ground screws on the printed circuit board.

The guy your dealing with at the parts store is an idiot.
Well I said that in my post...and my truck doesn't have a/c either.
Old 08-30-2010, 10:27 PM
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Thanks for the info. Americanmcs you said "The one on the left is the cold start injector sensor switch. The sensor on the right is the engine temp sensor for just the ecu." Are you sure the left one is the cold start injector switch? I ask because the coolant temp sensor everyone tries to give me has the same black plug as the sensor on the left, and looks similar.

The real problem I've been trying to figure out is my truck sputters and loses power after its been warmed up and then turned off for a few minutes, when you start it back up it misses a bit on accelleration and feels like it is losing power. Also if your puttering it around town, or have to sit at construction or something for a long time idling, it will do the same thing. I thought this might have something to do with the engine coolant temp sensor and it was a cheap part so I just tried it, but I can't figure out what sensor I need to use. Also I changed tps and adjusted it and changed the 02 sensor.


I bought the truck and drove it 10,000 miles and it blew a headgasket, I changed the head gasket and there was thick nasty grime in the intake manifold, 1/8 when you rub it it turns to a heavy oil, really nasty stuff. Could the intake air temp sensor be causing these problems? Any thing else you guys can think of? I cleaned out the iacv already.

I'm sorry to make this so long and rambling, thanks for your help.
Old 08-30-2010, 11:06 PM
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The one on the left is the thermal time switch, its in the same position on all 22RE`s. Are you sure the TPS is adjusted properly ?, and have you checked the timing to make sure its set right ?, and are the valves adjusted properly ?. Im just throwing out ideas and things to check.
Old 08-31-2010, 06:13 AM
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Originally Posted by DeadWrong
Thanks for the info. Americanmcs you said "The one on the left is the cold start injector sensor switch. The sensor on the right is the engine temp sensor for just the ecu." Are you sure the left one is the cold start injector switch? I ask because the coolant temp sensor everyone tries to give me has the same black plug as the sensor on the left, and looks similar.
Well The two sensors look the same except one has green plastic and the other has either brown or black plastic. I believe it is the thermo switch that is either brown or black. They technically are different in the fact that the resisitance they put out with the temperature of the coolant. The Engine coolant sensor has a much more broad spectrum of resistance. So i would not recommend interchanging them.
Old 08-31-2010, 08:38 AM
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I just replaced the tps last night. It was really hard to adjust, very touchy. I may try to adjust it again. I adjusted the valve lash after I replaced the head gasket, the timing isn't perfect but its very very close. The truck runs pretty great when you first start it up, just barely a little tiny miss you can feel if you have your hand on the engine or on the shifter every minute or so. Its only after you kill it and then start it back up when its warm that it starts acting weird, wants sputter bad and has a vibration in the engine when it starts running smooth enough it isn't lurching around

thanks a lot for all your help
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