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Discussion Starter · #1 ·
Hello!

So I have been driving this car for 9 months now without any hassle apart from the A/C compressor not kicking in (Sweden is only warm like 2 months in the summer). I remember noticing as with every other new civic owner that the temp gauge did not rest in the middle which I now know is completely normal. Car has done about 17000km (10500 miles)

Today when I parked the car and idled just before shutting it down I saw the temp was close to 3/4 and I got frightened and turned it off directly. I turned on the ignition and checked the temp with my ODB2 Bluetooth adapter and an app called car info and the temperature read around 110c. I went back in to read up on this and also let the car cool down for a while.

I then tried to check the coolant level which was impossible with a phone torch when it's dark outside (why the heck do they put it in a completely unavailable place???), I did however open the radiator cap and could see clear green fluid in there when I shook it a bit. I also checked the oil dipstick and filler cap for signs of "goo" but all seemed well.

In order to check if the fans work or not I took the car for another drive around with a mix of highway and stop-and-go traffic while monitoring the temp in carinfo. while driving on the highway all is well and it sits at 85-95c but when I reach city traffic the temp does reach 100c+. I notice the temp gauge move slightly but it is not as bad as before so I decided to stop and let it idle for a bit while opening the bonnet to check the fans. None of the fans were spinning even though the temperature was pending between 105-110c which I think is not normal? The temp gauge only seems to move from 1/3 when the temperature climbs past 105c. I will check the cables and fuses tomorrow I guess.

Another thing I noticed while driving home the first time was that when idling the cabin fan only blew cold air, but as quickly as I started moving again it became warmer. setting heat to "hi" did not make a difference in temperature in the OBD2 app by the way.

Could an A/C compressor not kicking in be part of this problem? I figured it wouldn't really matter if it kicked in or not as long as it doesn't disrupt the belt in any way.

The only thing different I can think of is that temperatures dropped suddenly from 10-15c to about 0-5c and I have not noticed this at all before.

-Does anyone have a good trick to check the coolant reservoir?
-Does this sound like a fan/sensor issue or should I consider the thermostat as well?
-From my understanding, the water pump and radiator should be working because temperatures drop at highway speeds?

Sorry for the long post. Any tip is deeply appreciated!
 

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i-Dtec
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and it sits at 85-95c
Thermostat opens at 82c on the 1.8 so thats pretty much normal operating temp.

Another thing I noticed while driving home the first time was that when idling the cabin fan only blew cold air, but as quickly as I started moving again it became warmer.
Ok this is a big flag for me. When I was on the Vectra forum we would see this quite a lot. The water pump had failed. When stationary there is no water flow at all, but for some reason, some rule of physics, water will start to move around the system when the car was moving. The water pump is driven off the Aux belt and is just above the AC compressor so isn't hard to swap.

None of the fans were spinning
The reason for this will be there is a Temp sensor on the bottom of the radiator. If the water is not flowing through the radiator the sensor wont read the temp and turn the fans on. Again might be pointing to a failed water pump. with the engine up to temp you should be able to see if the bottom radiator hose is hot, the top one will be, but if there is no flow the bottom one should be cold. Only way to feel the radiator would be to remove the plastic slam panel cover and see how much you can see of the radiator behind the AC condenser.

-Does anyone have a good trick to check the coolant reservoir?
Dont get hung up on the coolant reservoir. Its nothing more than an overflow tank, It certainly isn't an expansion tank, it wont hold any pressure at all. Any coolant entering it is only there because the pressure in the system forced open the radiator cap and allowed excess coolant out of the radiator. There is no way for coolant to return to the radiator once the radiator cap closes. The 2.2 has a proper expansion tank, the 1.8 does not. Even my 10th Gen 1.6 Diesel doesn't have an expansion tank, just an overflow tank.

clear green fluid in there
Btw thats the wrong coolant. Honda Type2 is Blue.
 

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Discussion Starter · #3 · (Edited)
Thermostat opens at 82c on the 1.8 so thats pretty much normal operating temp.
That's good

Ok this is a big flag for me. When I was on the Vectra forum we would see this quite a lot. The water pump had failed. When stationary there is no water flow at all, but for some reason, some rule of physics, water will start to move around the system when the car was moving. The water pump is driven off the Aux belt and is just above the AC compressor so isn't hard to swap.
Interesting, although I would have of course hoped for something easy like a blown fan or low coolant. Could driving without eganged A/C for long periods stress the water pump more?

The reason for this will be there is a Temp sensor on the bottom of the radiator. If the water is not flowing through the radiator the sensor wont read the temp and turn the fans on. Again might be pointing to a failed water pump. with the engine up to temp you should be able to see if the bottom radiator hose is hot, the top one will be, but if there is no flow the bottom one should be cold. Only way to feel the radiator would be to remove the plastic slam panel cover and see how much you can see of the radiator behind the AC condenser.
My ODB2 reader seems to be able to read it though? Or is it reading another sensor maybe?

Dont get hung up on the coolant reservoir. Its nothing more than an overflow tank, It certainly isn't an expansion tank, it wont hold any pressure at all. Any coolant entering it is only there because the pressure in the system forced open the radiator cap and allowed excess coolant out of the radiator. There is no way for coolant to return to the radiator once the radiator cap closes. The 2.2 has a proper expansion tank, the 1.8 does not. Even my 10th Gen 1.6 Diesel doesn't have an expansion tank, just an overflow tank.
So would me seing coolant in the rad cap be enough to know the system has sufficient amount of coolant?

Btw thats the wrong coolant. Honda Type2 is Blue.
Maybe ill need to check again but it looked green.

I think ill probably have it looked at, if it is the water pump ill try to get the parts needed and do the A/C compressor at the same time.
 

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i-Dtec
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Could driving without eganged A/C for long periods stress the water pump more?
Unlikely. They are both run from the Aux belt but that's as far as their relationship goes.
My ODB2 reader seems to be able to read it though? Or is it reading another sensor maybe?
Sorry, there are two temps sensors. One on the bottom of Radiator and one on the water housing outlet behind the Thermostat housing.
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So would me seing coolant in the rad cap be enough to know the system has sufficient amount of coolant?
Yes. When cold if the coolant is at the top of the radiator this is the correct level.
 

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Discussion Starter · #5 · (Edited)
Sorry, there are two temps sensors. One on the bottom of Radiator and one on the water housing outlet behind the Thermostat housing.
Do know which one my car scanner app reads? It's called car scanner, not car info like i wrote previously. I went for a drive again today but used my phone instead of head unit to connect to the ODB2 dongle. the temperature read 100c one time when I accelerated after a traffic light, When idling for 5 minutes it sat between 85-90c depending on my fan settings, it went down when i opened the hood. No fans turned on though. I see a temp drop when I put it from "lo" to "hi". Shouldn't both fans engage when its on "lo" with A/C on? Or does the A/C need to mechanically engage for that to happen? The temp gauge was solid as normal today. I also had full warm air coming through when idling today. shouldn't idle stress the cooling system the most? I did not drive as far as yesterday though, no full-on highway but probably 10km in total today.

Yes. When cold if the coolant is at the top of the radiator this is the correct level.
It was not like the cap was touching the coolant, no surface tension or anything but I guess it's fine. A local mechanic opened the rad cap while the engine was running (cold ofc) and said it looked fine. He also said it's normal for a temp gauge to climb in city traffic but I disagree so I won't be going back there.

This is temp gauge after idling for 5 min:

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I also tried to listen for anything weird in the engine bay but i think it's sounds fine? Ticks more than my old Saab but i heard these engines does that. Do i need a valve adjustment?


19 november 2022

Really scratching my head over this, thank you for your help so far.
 

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i-Dtec
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Do know which one my car scanner app reads?
Sorry, no.

Shouldn't both fans engage when its on "lo" with A/C on? Or does the A/C need to mechanically engage for that to happen?
I would expect for the fans to run when the AC is on the AC would need to be operating. Also at an outside temp of 2C the AC fans wont run anyway. Cooling AC doesn't operate below 5C on the civic iirc.

shouldn't idle stress the cooling system the most?
Well yes, but your outside temp is showing 2 degrees C, so that will also affect the engine temp. I'm sure if you took the revs up to 2500 and sat there the temp would rise.

He also said it's normal for a temp gauge to climb in city traffic but I disagree
I agree with you. In the 4 1/2 years I owned my 1.8 not once did I ever see temp gauge move past that "just below the half mark" even in the hot summer we had this year.

Look at the picture below. With the engine stone cold remove one end of this hose, either end. Then start the car. If the water pump is ok water should spray out at a reasonable rate. This is a bypass pipe that allow coolant to circulate around the system before the thermostat opens.
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My thermostat failed at 90k. Same symptoms as this.

Changed it out. All sorted. Easy to change as well. Get some Type 2 coolant from Honda before you start. 5l will do.

Start there. If you are getting EML codes it’ll be an electrical or sensor issue. But without, it won’t be that.

It’s also unlikely to be the water pump, as the blades are metal, not plastic, and you’d probably hear it failing. It’s also not easy to change as people are suggesting. It’s a pig of a job, with limited access. Unless you are very much car DIY inclined, I’d leave it.
 

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Discussion Starter · #8 ·
My thermostat failed at 90k. Same symptoms as this.

Changed it out. All sorted. Easy to change as well. Get some Type 2 coolant from Honda before you start. 5l will do.

Start there. If you are getting EML codes it’ll be an electrical or sensor issue. But without, it won’t be that.

It’s also unlikely to be the water pump, as the blades are metal, not plastic, and you’d probably hear it failing. It’s also not easy to change as people are suggesting. It’s a pig of a job, with limited access. Unless you are very much car DIY inclined, I’d leave it.
Thanks!

Problem is that I'm trying to find the right coolant here in Sweden but i have had no luck so far. A local dealer has a blue coolant with phosphate for Japanese cars and they spec Honda type 2 in the list so i guess that one could work. The thermostat seems easy enough to switch. I am going to try to check the water pump and see if bottom radiator hose is warm when under operating temp.

Could it be that my thermostat opens but not as much as needed on idle? Still does not explain why the fan doesn't turn on though?
 

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Thanks!

Problem is that I'm trying to find the right coolant here in Sweden but i have had no luck so far. A local dealer has a blue coolant with phosphate for Japanese cars and they spec Honda type 2 in the list so i guess that one could work. The thermostat seems easy enough to switch. I am going to try to check the water pump and see if bottom radiator hose is warm when under operating temp.

Could it be that my thermostat opens but not as much as needed on idle? Still does not explain why the fan doesn't turn on though?
Get coolant from the Honda dealer. Or on eBay.

Yeah, thermostat is easy. Just get a Honda one. Comes with the seal.

You’ll to remove engine undertray to access drain tap and allow coolant to flow out. Or you can drill some nice big holes out on the undertray with a holesaw.

Engine needs to get really hot to turn fans on. Also, ambient temps need to be high. Fan operations aren’t as simple as they used to be.
 

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Discussion Starter · #10 · (Edited)
Get coolant from the Honda dealer. Or on eBay.

Yeah, thermostat is easy. Just get a Honda one. Comes with the seal.

You’ll to remove engine undertray to access drain tap and allow coolant to flow out. Or you can drill some nice big holes out on the undertray with a holesaw.

Engine needs to get really hot to turn fans on. Also, ambient temps need to be high. Fan operations aren’t as simple as they used to be.
I let the engine heat up again and the top radiator hose is hot but the bottom one is stone cold... I also opened the rad cap before it reached normal operating temp (small explosion, I had a rag over it so nothing major happened) but there seems to be nothing flowing at all even when the water hit 90c on my reader, Water lies still. I drove for like 10 minutes in the city and out on the highway and back and it's already reaching 100c on the coolant temp. this time while driving in the city traffic gauge went up when driving around 20-30 and actually went down when idling again. Probably lost a little coolant when removing the rad cap.

If the thermostat is stuck in the closed position there would be no flow in the rad correct?

I should probably have consulted a mechanic already but I like to learn and to save money :rolleyes:.

Could I have damaged the engine already?
 

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I let the engine heat up again and the top radiator hose is hot but the bottom one is stone cold... I also opened the rad cap before it reached normal operating temp (small explosion, I had a rag over it so nothing major happened) but there seems to be nothing flowing at all even when the water hit 90c on my reader, Water lies still. I drove for like 10 minutes in the city and out on the highway and back and it's already reaching 100c on the coolant temp. this time while driving in the city traffic gauge went up when driving around 20-30 and actually went down when idling again. Probably lost a little coolant when removing the rad cap.

If the thermostat is stuck in the closed position there would be no flow in the rad correct?

I should probably have consulted a mechanic already but I like to learn and to save money :rolleyes:.

Could I have damaged the engine already?
You need to replace the thermostat. It’ll solve this issue. I 98.9% guarantee it.

Stop driving the car until it’s done. You probably haven’t damaged anything yet. But you will if you keep pushing it without cooling.
 

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Discussion Starter · #12 ·
You need to replace the thermostat. It’ll solve this issue. I 98.9% guarantee it.

Stop driving the car until it’s done. You probably haven’t damaged anything yet. But you will if you keep pushing it without cooling.
Yea i will not drive it, but moving it to somewhere better to do the work say a couple 100m won't be a death sentence I guess?

Now i just need to find someone who has OEM parts in Malmö where i live, the coolant seems to be green in my car so i guess it is not the blue type 2 one. It looks bluish on a piece of paper but not in the rad itself. Will draining and filling with Honda type 2 cause issues if its a green one at the moment? Or should i fill once before with distilled water and run it for a bit?
 

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Yea i will not drive it, but moving it to somewhere better to do the work say a couple 100m won't be a death sentence I guess?

Now i just need to find someone who has OEM parts in Malmö where i live, the coolant seems to be green in my car so i guess it is not the blue type 2 one. It looks bluish on a piece of paper but not in the rad itself. Will draining and filling with Honda type 2 cause issues if its a green one at the moment? Or should i fill once before with distilled water and run it for a bit?
Up to you. Definitely drain via the lowest point in the system. Personally I’d just fill it up with proper coolant after doing thermostat. Burp it. Job done.
 

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Just remove the thermostat and put it in a pan on the cooker and boil it, see if it opens. Even if the thermostat was stuck closed your heater would still work as normal as there are bypass pipes to allow coolant to flow around the system before the thermostat opens. You could also just refit the thermostat housing and leave the thermostat out and try again as well.
TBH the issue you have with coolant now is that you will always be mixing it. Honda type 2 comes premixed so you can not drain the system completely. From what I read online Honda Type 2 is a P-HOAT silicate free coolant. Try searching for this.
 

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Id look up your coolant rather than take for granted it's the same as UK models
We don't get the cold you will get in sweeten almost guaranteed you need a different 1 to what uk owners are recommending
Can rember my mate working for msport and testing in -20
Says was that cold everything hurt
 

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Discussion Starter · #17 ·
This looks a likely spot. Pop in and see if they can you the parts you need.

Honda at AUTOCLINIC IN MALMÖ
+46 40 93 14 50

Ill give em a call in the morning. Thanks

Just remove the thermostat and put it in a pan on the cooker and boil it, see if it opens. Even if the thermostat was stuck closed your heater would still work as normal as there are bypass pipes to allow coolant to flow around the system before the thermostat opens. You could also just refit the thermostat housing and leave the thermostat out and try again as well.
TBH the issue you have with coolant now is that you will always be mixing it. Honda type 2 comes premixed so you can not drain the system completely. From what I read online Honda Type 2 is a P-HOAT silicate free coolant. Try searching for this.

Heat does work, but once the gauge starts to climb out of the norm i get cold air.

I can get this locally, it specs the type 2 in the description. Since i will probably mix green with blue anyhow i might as well not hassle to get the OEM shipped here.

If i got my thermostat changed at this place they would use this one, and they would give me a warranty if they do the job.


Smart point regarding removing the current thermostat.




Id look up your coolant rather than take for granted it's the same as UK models
We don't get the cold you will get in sweeten almost guaranteed you need a different 1 to what uk owners are recommending
Can rember my mate working for msport and testing in -20
Says was that cold everything hurt
In Malmö i have not seen lower than -10 in 7 years so i think its ok
 

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It's possible that if it has had coolant added that isn't the correct sort that there has been a reaction between 2 different types of coolant - could have clogged the system. I think this is less than likely but something that you may need to consider.
 

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Discussion Starter · #20 ·
It's possible that if it has had coolant added that isn't the correct sort that there has been a reaction between 2 different types of coolant - could have clogged the system. I think this is less than likely but something that you may need to consider.
In the service documents, I see no proof of coolant ever being touched, according to the list for petrol you change it after 20.000 km or 10 years. 10 years have passed so I guess it's needed either way. Could a 12yo coolant change color slightly? Can anyone look into their Type 2 coolant from the rad and see if it appears blue or not?

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