Replacing Engine Coolant Temperature Sensor on 1999 Honda Civic

okay today I'm going to change out my engine coolant sensor temperature and that's right there you just squeeze this back to AB and it comes off and that's gonna believe believe that is a 19 millimeter so you she's a soccer that right now what I'm doing I'm just draining my radiator fluid so won't have so much spilling out of there you can see the upper radiator hose here so that's going to be higher than that and then we get that lower radiator hose it's not right lower does come out of the bottom radiator but it's almost in line he goes right back here it's almost in line with that so at first I was just going to squeeze my tubes and push the excess inside the um overflow here but I couldn't get enough out so what I did just now is I put a bucket down there and you can't see it but I can just reach in with my hand and at the bottom of the radiator there's just a little wingnut plastic wingnut a little bit worried it was going to break off it's kind of too hard to show you but just trust me it's down there you can just reach down there feel it maybe get a little mirror you can climb in underneath underneath your car over here and kind of see it and I also just put a little plastic bucket down there to catch it so just waiting for that radiator fluid to drain out they're not going to drain it all just enough to um or hopefully it gets below this point here I might be there and see what I'm doing now is I'm squeezing the hoses the bottom hose here see if I can push a little bit more fluid out of there okay at this point I just took my socket put it on there just need deep web socket and I just broke it loose and there you can see you can turn there put a rag there in case any fluid is going to spill out anyhow I'm going to do is take this off and put the new one in I'll show you that okay so it's a good thing I put that rag there because when I took that out I thought I'd drain enough fluid but apparently I didn't because I clued came gushing out of that thing so I repositioned my bucket underneath there to catch it actually the rag act like a ramp so it Ahnold the one spot and I just put the other one in real quick and so I'm going to dry that off and then probably when I get done I'll hose down the engine a little bit gets coolant off the components so just be give you a heads up you're gonna get a lot of fluid coming out of there and it was coming out bad anyhow so I picked this up here unfortunately I can't find my 19 millimeter deep socket 3/8 drive setup so I have to use a 1/2 inch which is like we're killing this but I just want to show you want to torque this and on mine it's a um it's a 30 foot pounds and this is for D 16 y7 you need to look up the torque specs for your particular engine and that's very little torque so it's important that though we're tighten it a lot of people are putting like Loctite and rubber gasket sealant and teflon tape and stuff like that that's all used on the other sensor this sensor actually sends a temperature gauge temperature to the ECU and I think that it's on that oh that's right back here I think is the other one and this one that one's used to actually control your temperature gauge which kind of doesn't do anything that's the one that takes all that Loctite and all nonsense but anyways just want to make sure you torque that on and again it's very low so don't reef that in there too tight okay because I got that flute all over I wiped it off the best go to the paper towel and then I just took some contact cleaner you get some using the CRC stuff here anyways I just sprayed it in here and then since that's cleaning I figured I might have clean this end too so I'm just waiting for that to evaporate there and then I'll put that back together and then after that I need to close that valve on the bottom there and then I'm going to put some the radiator fluid back in probably have to add a little bit top it off because it lost a little bit and then I'll finish up by just running some hose water in here to clean off any excess radiator fluid that's big okay what I did now is I took that like connector again then went in and turn on the turn on the heater turn it up on high you don't need the fan go on you see the heater turned up and it sucks come in yeah that goes I got like overflow containers anything you got a myth you know the maximum and I could be think I see it there just below the maximum so hopefully this is just going to take a little while basically going to need it up don't you the valve Oh Valve's all open up and stuff and and I could see quit seeing bubbles out of here them on the roof here's a little burp you know the air out of it anyway so that's what I'm doing now another bubble just finishing up here put my radiator cap back on I really wanted to run it to my fan caked on it's like really close but you need to back it up hose it off and then my I need to get a new radiator cap anyways there's no Sun little ring came off in there the time for new one of those and all the only other thing I did they stuck a scanner tool that I have in the ODB two connector and I cleared the check engine light for that sensor and so when I time we get back to the store everything's good that check in July should stay off anyway so that's about it

41 thoughts on “Replacing Engine Coolant Temperature Sensor on 1999 Honda Civic

  1. Need help. I have 98 civic LX. My car overheats slowly when idling but goes down slowly when driving. The fan works but I noticed it doesn't turn on until the temperature is high. Should I change the thermostat or the ECT switch? I don't think the ECT sensor would need to be changed since I don't have a check engine light right? No apparent leaks. Only concern is the overflow tank is very low.

  2. Great video! However guys if your temperature gauge in your car is not working please check the sensor to the left of the one he is swapping out. Mine was simply not connected and it worked instantly! And I only noticed it because the gentleman in the video made a comment about the sensor in this video!

  3. Would this sensor not working properly, have an affect on the AC not blowing cold, when it's hot outside? It blows cold cold mornings and nights. But warm air during the day.

  4. Would a bad sensor cause my car to read hot 5 min after idling? I have a 95 civic hatch and it goes way past the hot level within minutes of starting and its below freezing where i live. The motor doesnt feel like its over heating and its not making any funky smells like my old 240 that used to overheat

  5. Replaced mines as soon as code popped up for the sensor. After I replaced it, check engine light is still on for the same sensor code. Any ideas it might be?

  6. fixed it worked like a charm and it was easy too.
    a shop wanted at least $200 and I did it in 5 minutes
    thanks so much for your help

  7. Would the ECT sensor dictate the thermostat temperature? I've been stumped No check engine,
    Fan will not come on almost 3/4 to the red at times 2 lines from the red won't kick on the coolant fan, only time the coolant fan cycles on and off is when the heater is on, this is not normal?Only time it would work is when I turn the a/c on which manually turns both fans on condesner and coolant fan, both fans are new, radiator new, new rad cap, fresh coolant new water pump, new thermostat, head gasket seems OK no signs no bubbles or milky color or smell from exhaust or any coolant in oil mixed, so is this a failing ect sensor? Its a 05 Honda civic so most of the failing parts are intermittent, never just die.
    Quality Parts are Napa also OE and "new" to a year old. Condenser fan, water pump, thermostat is new and rad/coolant fan radiator and rest is about a year old it works and kicks on, just (not) when it gets hot. Please help.

  8. hello there is a smaller sensor to the left of it. it controls the needle on the temp gauge in cluster. what is it

  9. do u know the bolt size? the ect is? id rather run an after market gauge $25 ive been going through hell with my gauge and sensor

  10. Can you tell me if the control temperature gauge (finger touching at 3:42) if defective will cause oil leak?

    What is that part number?

    Also, do you know what is causing that engine noises?

    That is the one on the left side of the Engine Coolant Temperature Sensor.

    Nice & clean engine bay.

  11. is it necessary to drain the coolant from the radiator? can you just unscrew the old ect sensor and quickly insert the new sensor? i know coolant will come out but is it necessary to drain to avoid any damage? just curious


    Will this ECT work?

  13. @ChristiannGuitarDude Won't let me reply to your comment. This video should help:

  14. does a faulty ect on 97 civic ex cause the temperature gauge in the dash to go up and down sometimes? I've changed my thermostat, new water pump, radiator is new, fans come on (both ac and radiator), new radiator cap and the temperature gauge still goes up and down.

  15. tubejim question
    my car starts perfect cold. once warm it cranks but doesn't turn over? throws code 6 and 17(vss). 90 civic.

  16. I tried using a 3/8 19mm deep socket, but the socket won't pass the protruding end of the harness plug. Should I go with the 1/2 19mm deep socket? I tried using a 19mm wrench. I failed in that respect. So I'm stuck and I really need to do the smog test. I'm doing this job on my 1999 Acura Integra.

  17. Just so everyone whos having trouble knows, if your temp gauge isn't moving/radiator fan isn't kicking on replace the fan switch first, I replaced the part in this video and it didn't help (still a good vid) but I replaced the switch by the upper rad hose and now my fan is blowing and my temp gauge is moving.

  18. Does this sensor work the tempeture gauge on the dash? Help,i just got an awesome shape civic ex coupe,but temp gauge stays on cold and never moves

  19. Just changed ECTS on my 99 Saturn SC1, and was looking to see if it's tha same process for my son's 96 Accord LX, and yup, sure is…..a cute lil trick I did as far as spilling cooolant; I jacked my car up so that tha coolant would flow backwards, and I only had about as much coolant spill, as ur average 'nut' spews, haha……..nice vid

  20. Wow what a clean engine i would like to know how do you cleaned???? because it look really good i have the same car

  21. Thanks for the video man! I have a 99 as well. Do you happen to know where the temp SENDER switch is located? is it right next to that ECT? And do you know what that sensor is on the thermostat housing? Thanks again! Clean car by the way!

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