engine coolant temperature sensor
Burning Brakes
Joined: Jun 2014
Posts: 1,020
Likes: 51
From: Connecticut
I "think" you have to partially drain the coolant to pull the sensor.
Be careful with the plastic electrical connector when removing and replacing. It is usually brittle from heat and age.
Why do you think the sensor is bad?
Be careful with the plastic electrical connector when removing and replacing. It is usually brittle from heat and age.
Why do you think the sensor is bad?
Thread Starter
Drifting
Joined: Apr 2014
Posts: 1,396
Likes: 129
From: Plainfield IN
When the car is "cold" - hard to get started - runs a little rough but does not stall out - rev it up and there's hesitation - so I just let it idle - but strange thing the AC will blow warm air - once the temp gauge goes from "LO" to 140 the AC started blowing cold air and the engine idled smooth & normal. When the car is "hot" restarts fine - runs normal. This just started happening last weekend - prior no issues - has 95,000 miles on it. So I assume from a lot of reading that it's the temp sensor.
Burning Brakes
Joined: Jun 2014
Posts: 1,020
Likes: 51
From: Connecticut
Could be the temp sensor. I don't have my repair manuals handy so I can't give you any real advise. I would start there as the temp sensor is fairly cheap and it probably wouldn't hurt to drain and fill the coolant.
Now, having said that. I do not recall a "LO" being displayed either on the digital readout or the mechanical temp gauge. To what "LO" reading are you referring? I have a 96 so this could be a OBDII vs OBDI difference but I just want to clarify.
Now, having said that. I do not recall a "LO" being displayed either on the digital readout or the mechanical temp gauge. To what "LO" reading are you referring? I have a 96 so this could be a OBDII vs OBDI difference but I just want to clarify.
Team Owner
Joined: Feb 2003
Posts: 54,061
Likes: 9,395
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
does the analog and digital read out keep about 10* difference? is the check engine light on? if so what codes. if not why do you want to throw parts at it without going through the proper steeps called out in the FSM. the throwing parts at it until its fixed can get expensive
Thread Starter
Drifting
Joined: Apr 2014
Posts: 1,396
Likes: 129
From: Plainfield IN
Could be the temp sensor. I don't have my repair manuals handy so I can't give you any real advise. I would start there as the temp sensor is fairly cheap and it probably wouldn't hurt to drain and fill the coolant.
Now, having said that. I do not recall a "LO" being displayed either on the digital readout or the mechanical temp gauge. To what "LO" reading are you referring? I have a 96 so this could be a OBDII vs OBDI difference but I just want to clarify.
Now, having said that. I do not recall a "LO" being displayed either on the digital readout or the mechanical temp gauge. To what "LO" reading are you referring? I have a 96 so this could be a OBDII vs OBDI difference but I just want to clarify.
Until about 140 then shows numbers - this was last night - I'll check it again tonight.
Thread Starter
Drifting
Joined: Apr 2014
Posts: 1,396
Likes: 129
From: Plainfield IN
Well this is BS - she started right up and runs fine - AC - temp - everything. I did one thing I disconnected the coolant temp sensor plug and then plugged it back in - maybe some corrosion or now the stars are all lined up. Thoughts please.
Team Owner
Joined: Feb 2003
Posts: 54,061
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From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
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Race Director
Joined: Oct 2011
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From: Dallas Texas
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Mine went bad the start of this year. On cold start, coolant read 142. I did have a code for it. To be 100% sure, you'll need a scan tool to be sure. But I believe the FSM shows ohm readings for the coolant sensor. I didn't have to drain the coolant. None, in fact. I just put a lot of towels on top of the opti to be "safe". But when the sensor came out, almost no coolant came out. And no, car was not low on coolant.
You can scan codes on your 94 with a paper clip. Not to be a d1ck, but look up how to scan them for a 94. It's easy
Only reason I don't tell you, is because mine is a 93, and the paper clip goes in different pins than a 94.
You can scan codes on your 94 with a paper clip. Not to be a d1ck, but look up how to scan them for a 94. It's easy
Only reason I don't tell you, is because mine is a 93, and the paper clip goes in different pins than a 94.
Team Owner
Joined: Feb 2006
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From: San Antonio Texas
You don't have to drain the coolant, but the engine has to be COLD. Keep the coolant fill cap ON, don't open anything up and no air will get in to make the coolant flow out. When the engine is cold you can take the old sensor out with a minimum of coolant leaking out. Just have a rag under it to catch a little dribble and have the new sensor prepped and ready to stick in. You shouldn't loose more than a couple of tablespoons of coolant!