DIY Coolant Temperature Sensor change (PICS)
10-15-13, 09:39 PM
#181
Lexus Champion
I would say 40-45% of full temp gauge is about the perfect spot, and where you live doesn't affect engine temperature, if things are working right!
10-16-13, 04:38 AM
#182
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Well I went ahead and did it anyway since my car is averaging 15.1 US MPG over 4500miles (from my fuelly.com account).
I honestly regret doing it though, it took me over 3 hours for the job!
And I caused some damage too
Basically to change this sensor, all the sparkplug covers need to come out.
The sucky bit was the coilpack, I couldn't turn 1 of the 4 screws on the coilpack cover as the screw has softened from the years being in the heat, so I couldn't get my screwdriver to grip on the screw.
So I decided to take off the coilpack bracket, but the years in the heat has made the plastic connector to the coilpack brittle. Just a little tug broke it, and it broke further in my hands.
Otherwise the coolant temp sensor itself was easy to remove and replace. It needs a 19mm DEEP socket which usually will need a torque wrench, not a normal wrench.
I then reconnected the coilpack to terminals (with whats left of the plastic connector) and said a little prayer.
Happily the car started fine.
Might just be a placebo effect but the car feels punchier and the throttle seems more responsive. Time will tell what mpg I get (I had new spark plugs installed 2 weeks ago).
Pic shows the broken coilpack connector and the old coolant temp sensor.
I honestly regret doing it though, it took me over 3 hours for the job!
And I caused some damage too
Basically to change this sensor, all the sparkplug covers need to come out.
The sucky bit was the coilpack, I couldn't turn 1 of the 4 screws on the coilpack cover as the screw has softened from the years being in the heat, so I couldn't get my screwdriver to grip on the screw.
So I decided to take off the coilpack bracket, but the years in the heat has made the plastic connector to the coilpack brittle. Just a little tug broke it, and it broke further in my hands.
Otherwise the coolant temp sensor itself was easy to remove and replace. It needs a 19mm DEEP socket which usually will need a torque wrench, not a normal wrench.
I then reconnected the coilpack to terminals (with whats left of the plastic connector) and said a little prayer.
Happily the car started fine.
Might just be a placebo effect but the car feels punchier and the throttle seems more responsive. Time will tell what mpg I get (I had new spark plugs installed 2 weeks ago).
Pic shows the broken coilpack connector and the old coolant temp sensor.
10-16-13, 06:43 AM
#183
Lexus Champion
Might just be a placebo effect but the car feels punchier and the throttle seems more responsive.
I honestly regret doing it though, it took me over 3 hours for the job!
it can be very hard to believe, but with years of practice along with certain tools that you are unaware even exist, this job can be gotten down to less than 15 minutes, and that is even considered leisurely*
*I once set some A/C servicing records at Brown & Brown Chevrolet in Phoenix which was the largest car dealership in the world at that time - we had 150 service bays and 4 full time A/C mechanics who did nothing but A/C, and it is rare for a dealership to have any A/C specialists and we had 4!
so we had speed record contests, because we were doing always the same vehicles (Chevy pickup trucks mostly) - got the record for evacuate A/C, replace A/C compressor and clutch, O-rings, accumulator, orifice tube (located in difficult spot behind turn signal in grill) and recharge system in 34:07 minutes for a new Chevy truck - the flag hour time was 2.6 hours in the book! - they posted my record in on their wall and it still stands today! (to achieve this record, I had a $6000 Robinaire A/C machine, you have to be wrenching during evacuation and recharge to make it in time)
the moral of the story is, if you keep working on your car regularly and keep acquiring new interesting tools, these 3 hour jobs will become as fast and easy as changing the oil! (although I still hate changing the starter on LS400, now that is a job that if you do in 3 hours, you should feel proud! - lol)
Last edited by LScowboyLS; 10-16-13 at 12:42 PM.
10-16-13, 12:36 PM
#184
Pole Position
Basically to change this sensor, all the sparkplug covers need to come out.
The sucky bit was the coilpack, I couldn't turn 1 of the 4 screws on the coilpack cover as the screw has softened from the years being in the heat, so I couldn't get my screwdriver to grip on the screw.
So I decided to take off the coilpack bracket, but the years in the heat has made the plastic connector to the coilpack brittle. Just a little tug broke it, and it broke further in my hands.
I then reconnected the coilpack to terminals (with whats left of the plastic connector) and said a little prayer.
You dont take apart the coil, you remove it from the bracket like you did eventually. (Ya learn something new every day 
)Buy a new coil wire. (Full set of wires would be better) That broken coil wire isn't gonna stay hooked up for too long. It will start to arc and run like crap. So you're gonna need to change it anyway.
Don't regret your work, that old ECT doesn't look good at all and needed to be changed.
10-16-13, 12:44 PM
#185
Lexus Champion
10-16-13, 04:20 PM
#187
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Thanks for the good advice LScowboyLS and deanshark 
The big connector that goes into the coil was fine, only broke the plastic holder that tightens into the bracket.
However I am worried about the smaller 2-pin connector that goes into the coilpack under the bigger connector. What does this do?
The big connector that goes into the coil was fine, only broke the plastic holder that tightens into the bracket.
However I am worried about the smaller 2-pin connector that goes into the coilpack under the bigger connector. What does this do?
12-11-13, 02:08 PM
#190
Driver School Candidate
i know you guys swear by OEM, but ive read a lot around that people been using the duralast autozone or oriellys sensor and it works fine. i checked in with my local lexus and its about 70 for the sensor but my local autozone has it for 20...
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Oseberg (01-11-17)
01-04-14, 10:01 PM
#191
Driver School Candidate
Well, I'm about to brave this task tomorrow on my '95 LS400 with 190k and running smooth, except for a higher idle at start up until the car gets up to temp, lets see if this will help a bit, either way i think it'll be a good change! Great posts and info, not to mention pics
01-05-14, 01:32 AM
#192
Lexus Champion
01-05-14, 09:39 AM
#194
Lexus Champion
show me the link, you may have actually bought the real OEM part, seems like that is one of the names they go by! (haven't had my coffee yet, so no memory!)