DIY Coolant Temperature Sensor change (PICS)
#271
Driver School Candidate
Join Date: Dec 2015
Location: California
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I'd also suggest replacing the thermostat for good measure. Glad it's working out for you!
Hello to anyone with a rough Idle/low power Issue. I want to report my experience of changing the water temperature sender/sensor. It does make a difference.
My car has 129xxx miles on it. When cold starting the motor, it used to idle high for over 10 minutes.The temperature gauge climbed very slowly, and I never thought anything of it.
Because the temperature was not climbing fast enough, the computer added fuel to the mixture to compensate for an incorrect reading of the temperature sender/sensor. Its programmed to raise the idle when the motor is cold. This resulted in a warm motor being fed too much fuel, and it also made a good stink. I never experienced smoke, and eventually the idle would go down.
Even though the idle went down to the normal range of about 640 RPM after about 10 minutes, replacing the sensor has caused the engine to run much better throughout the RPM range.
I suspect that with the new sensor in place, the computer is receiving a more accurate reading of the water temperature.
Thanks for the advise, for now the problem seems to be fixed.
TIP: Use a 3/4 inch deep socket, with a 6'' or longer extension. If you do this, you may not have to remove the spark plug wires, or the plastic bridge that holds them in place on the front side of the motor. You can push them aside very gently, and remove the sensor.
I bought an OEM duplicate for $22.00 + 9% Tax. It was the same color as the original, and seemed to be well built. The original sensor was 25 years old. The wire connection base on the plug itself was quite LOOSE.
After doing this, I will begin to replace a few more sensors If I have the time and extra money. Being that Lexus has such quality standards, all of them are most likely 25 years old.
Thanks again, Joseph
My car has 129xxx miles on it. When cold starting the motor, it used to idle high for over 10 minutes.The temperature gauge climbed very slowly, and I never thought anything of it.
Because the temperature was not climbing fast enough, the computer added fuel to the mixture to compensate for an incorrect reading of the temperature sender/sensor. Its programmed to raise the idle when the motor is cold. This resulted in a warm motor being fed too much fuel, and it also made a good stink. I never experienced smoke, and eventually the idle would go down.
Even though the idle went down to the normal range of about 640 RPM after about 10 minutes, replacing the sensor has caused the engine to run much better throughout the RPM range.
I suspect that with the new sensor in place, the computer is receiving a more accurate reading of the water temperature.
Thanks for the advise, for now the problem seems to be fixed.
TIP: Use a 3/4 inch deep socket, with a 6'' or longer extension. If you do this, you may not have to remove the spark plug wires, or the plastic bridge that holds them in place on the front side of the motor. You can push them aside very gently, and remove the sensor.
I bought an OEM duplicate for $22.00 + 9% Tax. It was the same color as the original, and seemed to be well built. The original sensor was 25 years old. The wire connection base on the plug itself was quite LOOSE.
After doing this, I will begin to replace a few more sensors If I have the time and extra money. Being that Lexus has such quality standards, all of them are most likely 25 years old.
Thanks again, Joseph
#272
Driver School Candidate
This is a most interesting thread. I am looking forward (when the current cold/wet weather system is over) to replace mine on my 97 LS400. I have one question. Who has experience with the aftermarket sensors and what do you recommend? My local dealer stated that the coolant temperature sensor would have to be ordered and priced it (over the phone) as "above 100 dollars and under 500. We won't know till it comes in". To say the least, I'm not interested in getting it from them!
#273
It amazes me how many failed Engine Coolant Temperature Sensors people are experiencing. Since they were all original sensors that are OEM, and they all failed, I wonder why nobody has yet realized that the OEM sensors are crap and should be avoided.
How many other sensors in this engine are as crappy as this OEM temperature sensors? If they were all this crappy, none of your engines would run and you would all be experiencing all sorts of strange symptoms daily. Don't you think?
I would seriously think about avoiding the OEM sensor and go with something different that might have a chance of being much more reliable. Why would anyone want to buy an OEM part with such a high failure rate?
How many other sensors in this engine are as crappy as this OEM temperature sensors? If they were all this crappy, none of your engines would run and you would all be experiencing all sorts of strange symptoms daily. Don't you think?
I would seriously think about avoiding the OEM sensor and go with something different that might have a chance of being much more reliable. Why would anyone want to buy an OEM part with such a high failure rate?
Last edited by Oseberg; 01-11-17 at 06:08 AM.
#274
It amazes me how many failed Engine Coolant Temperature Sensors people are experiencing. Since they were all original sensors that are OEM, and they all failed, I wonder why nobody has yet realized that the OEM sensors are crap and should be avoided.
How many other sensors in this engine are as crappy as this OEM temperature sensors? If they were all this crappy, none of your engines would run and you would all be experiencing all sorts of strange symptoms daily. Don't you think?
I would seriously think about avoiding the OEM sensor and go with something different that might have a chance of being much more reliable. Why would anyone want to buy an OEM part with such a high failure rate?
How many other sensors in this engine are as crappy as this OEM temperature sensors? If they were all this crappy, none of your engines would run and you would all be experiencing all sorts of strange symptoms daily. Don't you think?
I would seriously think about avoiding the OEM sensor and go with something different that might have a chance of being much more reliable. Why would anyone want to buy an OEM part with such a high failure rate?
#275
Pole Position
It amazes me how many failed Engine Coolant Temperature Sensors people are experiencing. Since they were all original sensors that are OEM, and they all failed, I wonder why nobody has yet realized that the OEM sensors are crap and should be avoided.
I would seriously think about avoiding the OEM sensor and go with something different that might have a chance of being much more reliable. Why would anyone want to buy an OEM part with such a high failure rate?
I would seriously think about avoiding the OEM sensor and go with something different that might have a chance of being much more reliable. Why would anyone want to buy an OEM part with such a high failure rate?
Calliope: The aftermarket sensors are fine. Never had a problem with the one I put in my 93 LS. (or my 3 kid's cars) I think I paid $17 at Autozone, but that was about 6 years ago. Not sure what it would cost for your 97.
#276
Do you seriously believe that boiling water is that hot? And a temperature sensor is that complicated?
There is NO reason why it should cost more than $10 to make a temperature sensor that would last 100 years in boiling water with a failure rate above 1%. The ONLY reason the OEM parts are all failing is because they ARE CRAP!
There is NO reason why it should cost more than $10 to make a temperature sensor that would last 100 years in boiling water with a failure rate above 1%. The ONLY reason the OEM parts are all failing is because they ARE CRAP!
#277
Hey guys. I know this is an old thread but I figured I should put my question here rather than making a new post.
So I went to do this job today and I got to the sensor. However, I gently tried to remove it with pliers and it immediately started falling apart because it's dry rotted. I don't think it has ever been changed in this 200k mile Florida car.
My question: what is the proper way to unhook the wire from the sensor? I assume I have to push something in as I disconnect it? Or does it simply pull out? I definitely don't want to break the connector and have a bigger problem. Any tips?
Also, it took a lot to get to the sensor so I made a "shortcut" for next time by cutting off just enough of the plastic wire holder that the wires are still on plastic but I should have the space to get to the sensor. Really bad idea?
So I went to do this job today and I got to the sensor. However, I gently tried to remove it with pliers and it immediately started falling apart because it's dry rotted. I don't think it has ever been changed in this 200k mile Florida car.
My question: what is the proper way to unhook the wire from the sensor? I assume I have to push something in as I disconnect it? Or does it simply pull out? I definitely don't want to break the connector and have a bigger problem. Any tips?
Also, it took a lot to get to the sensor so I made a "shortcut" for next time by cutting off just enough of the plastic wire holder that the wires are still on plastic but I should have the space to get to the sensor. Really bad idea?
#278
I answered my own question. There's a clip you press down as you lift up.
I wouldn't recommend the shortcut of cutting a hole unless you can get yours bigger (it's hard with the wires right there).
First of all, the old sensor fell apart into DUST (the plastic part). Then I had a problem where my deep socket wouldn't go on the new sensor... Oh yeah, half of the old one is still in it. I connected it and left it because I had to drive somewhere. I also couldn't give it a good turn to tighten it - because of the space, I was risking breaking off the plastic piece. I will fix this but I made sure it's not leaking. My temp gauge still isn't working. In retrospect, I should've looked at the connecting piece - it probably has old sensor dust covering the metal. Will report when I feel like messing with it. I can't stand dry rot!
What happens if I break the connector that slips onto the sensor? It seems like it could break easily and then am I screwed or will the car run?
I wouldn't recommend the shortcut of cutting a hole unless you can get yours bigger (it's hard with the wires right there).
First of all, the old sensor fell apart into DUST (the plastic part). Then I had a problem where my deep socket wouldn't go on the new sensor... Oh yeah, half of the old one is still in it. I connected it and left it because I had to drive somewhere. I also couldn't give it a good turn to tighten it - because of the space, I was risking breaking off the plastic piece. I will fix this but I made sure it's not leaking. My temp gauge still isn't working. In retrospect, I should've looked at the connecting piece - it probably has old sensor dust covering the metal. Will report when I feel like messing with it. I can't stand dry rot!
What happens if I break the connector that slips onto the sensor? It seems like it could break easily and then am I screwed or will the car run?
#279
On 1990 to 1992 anyway. There are 2 temp sensors in there, the smaller one is for the gauge and the larger is the engine sensor. If I remember the small one has one wire and disconnects easy pull off, the engine temp on you do push and unplug it. I have only done the job with all the wires out of the way so its not a super simple job.
#280
On 1990 to 1992 anyway. There are 2 temp sensors in there, the smaller one is for the gauge and the larger is the engine sensor. If I remember the small one has one wire and disconnects easy pull off, the engine temp on you do push and unplug it. I have only done the job with all the wires out of the way so its not a super simple job.
#281
A lot of those connectors turn to DUST after a while. When I went to change my alternator it basically broke into about 100 pcs. I think Toyota used some crappy plastic that just couldn't take the heat cause in my opinion, I don't care if car is 100 years old, that should NEVER happen.
Luckily found a replacement connector on eBay that was relatively inexpensive. Hope you can get your issue solved and sorry I can't offer any advice except to say you may want to search eBay to see if there's a seller offering the connector you just destroyed!!!
Luckily found a replacement connector on eBay that was relatively inexpensive. Hope you can get your issue solved and sorry I can't offer any advice except to say you may want to search eBay to see if there's a seller offering the connector you just destroyed!!!
Hey guys. I know this is an old thread but I figured I should put my question here rather than making a new post.
So I went to do this job today and I got to the sensor. However, I gently tried to remove it with pliers and it immediately started falling apart because it's dry rotted. I don't think it has ever been changed in this 200k mile Florida car.
My question: what is the proper way to unhook the wire from the sensor? I assume I have to push something in as I disconnect it? Or does it simply pull out? I definitely don't want to break the connector and have a bigger problem. Any tips?
Also, it took a lot to get to the sensor so I made a "shortcut" for next time by cutting off just enough of the plastic wire holder that the wires are still on plastic but I should have the space to get to the sensor. Really bad idea?
So I went to do this job today and I got to the sensor. However, I gently tried to remove it with pliers and it immediately started falling apart because it's dry rotted. I don't think it has ever been changed in this 200k mile Florida car.
My question: what is the proper way to unhook the wire from the sensor? I assume I have to push something in as I disconnect it? Or does it simply pull out? I definitely don't want to break the connector and have a bigger problem. Any tips?
Also, it took a lot to get to the sensor so I made a "shortcut" for next time by cutting off just enough of the plastic wire holder that the wires are still on plastic but I should have the space to get to the sensor. Really bad idea?
#282
Pole Position
A lot of those connectors turn to DUST after a while. When I went to change my alternator it basically broke into about 100 pcs. I think Toyota used some crappy plastic that just couldn't take the heat cause in my opinion, I don't care if car is 100 years old, that should NEVER happen.
Luckily found a replacement connector on eBay that was relatively inexpensive. Hope you can get your issue solved and sorry I can't offer any advice except to say you may want to search eBay to see if there's a seller offering the connector you just destroyed!!!
Luckily found a replacement connector on eBay that was relatively inexpensive. Hope you can get your issue solved and sorry I can't offer any advice except to say you may want to search eBay to see if there's a seller offering the connector you just destroyed!!!
Rokas; You should go to the junkyard and grab some extra connectors (if they're good) for stuff that you might be taking off so you have extras for when another "turns to dust" like the first one did. If it happened to one, it's gonna happen to another.
#284
Toyota, Crappy plastic? You think this only happens on Toyota products? Do you also think they used crappy rubber for all the vacuum lines? Those also get hard and brittle so they crack. Everything wears out over time, especially with all the heat in the engine bay.
Rokas; You should go to the junkyard and grab some extra connectors (if they're good) for stuff that you might be taking off so you have extras for when another "turns to dust" like the first one did. If it happened to one, it's gonna happen to another.
Rokas; You should go to the junkyard and grab some extra connectors (if they're good) for stuff that you might be taking off so you have extras for when another "turns to dust" like the first one did. If it happened to one, it's gonna happen to another.
The closest junkyard to me with an LS400 is 2 hours away.
If the connector breaks, how hard is it to change?
Like I said, mine didn't. But now I have the Temp Sender for the gauge that I want to put in and THAT connector seems to come off differently... Do I have to twist it or something? I wasn't about to yank it, you know. I got it to move a couple mm and it doesn't want to fully come off apparently.
I wish I could see a diagram of how these connectors are set up!! If I knew how they lock onto the sensor, I woudn't have to risk breaking them! The question is: Does it pull right off? The connector for the Sender. Or do you twist and pull or something else?
If I had a second car that's running, I would just go for it and replace the connector if I need to but the problem is that me and my wife are being kicked out of our home with 5 days notice and we NEED this car running.
I would try it if someone knew FOR SURE that the car would still run without the Engine Temp Sender (again, the one for the gauge in the dash - not the Coolant Temp Sensor) being connected - then I could take the chance of it breaking...
#285
i replaced the Coolant temp sensor on my 98 ls400 with 180k miles today. Replacement was fairly easy. lost just a very small amount of coolant during the change. I should have waited to let the car cool down a little more before swapping the ECT sensor. anyways my question is the following:
I ordered the OEM toyota ECT sensor part number :
also is it required for me to reset the ECU ? if so which fuses do i need to pull ?
thanks
I ordered the OEM toyota ECT sensor part number :
89422-30030
is there supposed to be a washer or gasket that is supposed to be used with this sensor? The old one i removed did not have a washer/gasket that was used with it. The new one did not come with any sort of washer.also is it required for me to reset the ECU ? if so which fuses do i need to pull ?
thanks