car overheats, heater is cold... thermostat?
#26
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Re: car overheats, heater is cold... thermostat?
sounds like you have no water/anti-freeze in your motor... i had that problem on my old motor... but just get a new thermostat and see if that fixes it... haveing no thermostat would mean your engine wouldnt warm up... at all! unless you were at idle stopped... i got my eg with no thermostat and couldnt think of why my heater wasnt blowing warm air... just cold... thats what happens when you got no thermostat
#27
Re: car overheats, heater is cold... thermostat?
sounds like you have no water/anti-freeze in your motor... i had that problem on my old motor... but just get a new thermostat and see if that fixes it... haveing no thermostat would mean your engine wouldnt warm up... at all! unless you were at idle stopped... i got my eg with no thermostat and couldnt think of why my heater wasnt blowing warm air... just cold... thats what happens when you got no thermostat
Sounds like a blockage to me. Thermostat doesnt sound like it has anything to do with it. If you've replaced the thermostat and everything then it wont be that, unless you put it on backwards. Even then it shouldnt cause the problems you are having.
I would vote for either a lot of air in your cooling system, or a blocked rad core or similar. The heater thing will just be a problem by proxy for some reason like the water getting too hot, creating pressure + air in places.
Just my 2c though. Good luck mang
EDIT: Also, I believe there is a ground wire on the thermostat too, make sure that is connected up.
#28
Honda-Tech Member
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Re: car overheats, heater is cold... thermostat?
Muahahahaha!!! I have diagnosed the car and think I fixed it. I took off a radiator hose and examined the flange I thought it was leaking from. The flange was all corroded and rough so I sanded it down and re-connected the hose.
When I drained to coolant to clean off the flange, I was surprised that I only took out like 3 cups of coolant. There was like 10% of what there should have been in there. This means I was leaking coolant.
I started the car and got it hot, then examined where I cleaned the flange and heard/saw steam and water spraying out. The flange/hose I cleaned appeared to be a good seal, but the top radiator hose was pissing water from where it connected to the motor.
The coolant leaks out, then the motor overheats because there is no coolant in the system. Pretty damn simple...
thanks for all the replies, the problem is fixed - but with all the intel in this thread one could probably fix just about any cooling problem in their car. bookmarked for further problem-solving.
thanks so much, honda-tech
When I drained to coolant to clean off the flange, I was surprised that I only took out like 3 cups of coolant. There was like 10% of what there should have been in there. This means I was leaking coolant.
I started the car and got it hot, then examined where I cleaned the flange and heard/saw steam and water spraying out. The flange/hose I cleaned appeared to be a good seal, but the top radiator hose was pissing water from where it connected to the motor.
The coolant leaks out, then the motor overheats because there is no coolant in the system. Pretty damn simple...
thanks for all the replies, the problem is fixed - but with all the intel in this thread one could probably fix just about any cooling problem in their car. bookmarked for further problem-solving.
thanks so much, honda-tech
#29
Re: car overheats, heater is cold... thermostat?
I wanted to add my experience with my 2007 Honda Accord.
I was having intermittent overheating issues combined with a non-functioning heater. I believe that there is a direct relationship between these two issues. It is likely that when your car overheats there is a mechanism whereby the car stops the flow of coolant to the heater core. This makes sense as high temperature coolant could damage to the core and lead to high temperature fluid inside the cabin. Therefore I determined that it was likley an issue with the cooling system.
I added coolant to the max line of the reservoir tank and I still had the issue. Then I let the car cool and then checked the fluid level and added more Genuine Honda coolant directly into the radiator by removing the cap. I started the car cold and followed the procedure that you would follow to fill the cooling system after a flush. The radiator accepted a considerable amount of new fluid. This solved the overheating and heater issues.
It is likely that I have a small hole in the radiator and that it will have to be replaced. I let the reservoir get low enough that the radiator was unable to pull fluid back into the system properly and this permitted low levels of coolant in the system leading to sporadic overheating and heater core shutdown.
If you have similar issues then make sure your car’s cooling system is functioning properly before you move forward with costly heater core repairs. You can use an infrared thermometer gun ($20 Amazon) to help diagnose problems and this will save your considerable time and money. There are many guides on the internet to help you with the diagnosis process.
Troubleshoot Engine with Infrared Thermometer
I was having intermittent overheating issues combined with a non-functioning heater. I believe that there is a direct relationship between these two issues. It is likely that when your car overheats there is a mechanism whereby the car stops the flow of coolant to the heater core. This makes sense as high temperature coolant could damage to the core and lead to high temperature fluid inside the cabin. Therefore I determined that it was likley an issue with the cooling system.
I added coolant to the max line of the reservoir tank and I still had the issue. Then I let the car cool and then checked the fluid level and added more Genuine Honda coolant directly into the radiator by removing the cap. I started the car cold and followed the procedure that you would follow to fill the cooling system after a flush. The radiator accepted a considerable amount of new fluid. This solved the overheating and heater issues.
It is likely that I have a small hole in the radiator and that it will have to be replaced. I let the reservoir get low enough that the radiator was unable to pull fluid back into the system properly and this permitted low levels of coolant in the system leading to sporadic overheating and heater core shutdown.
If you have similar issues then make sure your car’s cooling system is functioning properly before you move forward with costly heater core repairs. You can use an infrared thermometer gun ($20 Amazon) to help diagnose problems and this will save your considerable time and money. There are many guides on the internet to help you with the diagnosis process.
Troubleshoot Engine with Infrared Thermometer
#30
Honda-Tech Member
iTrader: (1)
Re: car overheats, heater is cold... thermostat?
LOL
6 YEAR OLD THREAD
Applause for trying to help, but read the rules before doing so. OP even stated he fixed the problem.
Rules: https://honda-tech.com/honda-civic-d...sting-3002401/
6 YEAR OLD THREAD
Applause for trying to help, but read the rules before doing so. OP even stated he fixed the problem.
Rules: https://honda-tech.com/honda-civic-d...sting-3002401/
#31
Re: car overheats, heater is cold... thermostat?
Thank you for letting me know this info.........Just got a 97 Accord as a project car and this just gave me an exact troubleshooting procedure
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