Engine Overheating Mystery
#1
Registered!!
Thread Starter
Join Date: May 2009
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Engine Overheating Mystery
Car:
2000 Honda Civic EX, 1.6L 127 hp I4, 4-Speed Automatic Overdrive, 98K miles
Issue:
My 2000 civic is overheating. I have had this problem for around 2.5 years. I'm not sure what could have caused the problem - one day while driving, I just noticed that the temp gauge was approaching the red. My driving habits hadn't changed (average around 5k/year mixed city and freeway driving), nor had anything (i.e. damage, collisions, etc.) happened to the car.
The car tends to overheat after about 15 minutes of city driving, but has overheated on the freeway, as well (this occurs less frequently, however, because the constant air flow when traveling seems to keep the engine cooler). When the car overheats, the cooling fans will not turn on. To cool the car down when it overheats, I will turn the heater on high. Upon doing this, the temperature gauge will drop fairly quickly; however, I must then keep the heater on to prevent the car from overheating any further.
When the car overheats (while the car is parked with the engine running), the temperature gauge will rise about 8/10 of the way up, then the fan(s?) will kick on. The temp gauge will then fall to about the midway point. The fans will then shut off, and the temp will rise again. This cycle lasts around 3-5 minutes and will repeat itself for however long the car is running.
Repairs:
I have taken my car to several mechanics, yet NONE has been able to diagnose or reproduce the problem. Every time the car is in the shop, the fans will turn on properly. The last mechanic I took my car to even drove the car around town a few times, but never witnessed the car overheat until I drove the car directly to the shop myself after it had already overheated.
The first set of repairs I had done to address this issue were: coolant/radiator flush, new thermostat, new timing belt, new waterpump, new alt. drive belt, new p.s. drive belt, and new a.c. drive belt. Also, the mechanic inspected to make sure that there were no blockages in the hoses. I’m not sure if each of these was done to address the issue, specifically, or if they were done simply as some sort of maintenance. Either way, these repairs did not solve the problem. My car would still overheat.
The second set of repairs was done 9 months later. This time I had the coolant fan switch replaced. This seemed to fix the problem. My car didn’t overheat for nearly a year. Well, a few weeks ago, it began overheating again, and so I took it to a different mechanic.
The third, and most recent, set of repairs involved replacing the entire fan motor unit, the fan switch, and the thermostat (again). These mechanics said that although they weren’t sure what the problem was or how to reproduce it, the repairs they made should fix the problem. They didn’t. The car overheated on the way back.
Other Notes:
The coolant level has always remained stable throughout this ordeal.
The radiator has never appeared to malfunction (after speaking with the mechanics about overheating, some suggested feeling if the radiator had any cold spots between the fins. Mine did not. Nor has any mechanic felt that this problem lay with my radiator or engine…granted, they had no idea what the problem was, I just felt that I should point this out, for what it’s worth).
The oil has always remained the same color (the color of oil – not milky or grimy); however, after the car overheats, the oil level tends to drop slightly. The car is not leaking oil, however – or at least that I can tell. There have been no oil stains, residue, or drops underneath my car noticed by me or any of the mechanics I have used.
The car can produce a smell when overheating. Usually it smells sort of metallic. The mechanics I’ve used said this smell was boiling coolant.
After taking the car home from the mechanic, it overheated again. I pulled over to look at the engine. I noticed neither fan was on. I turned the heater on, then both fans switched on. I turned the heater off, then both fans switched off. I turned the air conditioner on, then the driver’s-side fan switched on. I turned the air conditioner off, then the driver’s side fan switched off. The same happened when I turned the fan on and off (the coolest setting without using the air conditioner). I then turned the heater back on, but this time only the driver’s side fan would turn on. I’m not sure if this is what happens each time my car overheats, but I did notice it today and have noticed that my fans weren’t on upon prior occurrences of overheating.
2000 Honda Civic EX, 1.6L 127 hp I4, 4-Speed Automatic Overdrive, 98K miles
Issue:
My 2000 civic is overheating. I have had this problem for around 2.5 years. I'm not sure what could have caused the problem - one day while driving, I just noticed that the temp gauge was approaching the red. My driving habits hadn't changed (average around 5k/year mixed city and freeway driving), nor had anything (i.e. damage, collisions, etc.) happened to the car.
The car tends to overheat after about 15 minutes of city driving, but has overheated on the freeway, as well (this occurs less frequently, however, because the constant air flow when traveling seems to keep the engine cooler). When the car overheats, the cooling fans will not turn on. To cool the car down when it overheats, I will turn the heater on high. Upon doing this, the temperature gauge will drop fairly quickly; however, I must then keep the heater on to prevent the car from overheating any further.
When the car overheats (while the car is parked with the engine running), the temperature gauge will rise about 8/10 of the way up, then the fan(s?) will kick on. The temp gauge will then fall to about the midway point. The fans will then shut off, and the temp will rise again. This cycle lasts around 3-5 minutes and will repeat itself for however long the car is running.
Repairs:
I have taken my car to several mechanics, yet NONE has been able to diagnose or reproduce the problem. Every time the car is in the shop, the fans will turn on properly. The last mechanic I took my car to even drove the car around town a few times, but never witnessed the car overheat until I drove the car directly to the shop myself after it had already overheated.
The first set of repairs I had done to address this issue were: coolant/radiator flush, new thermostat, new timing belt, new waterpump, new alt. drive belt, new p.s. drive belt, and new a.c. drive belt. Also, the mechanic inspected to make sure that there were no blockages in the hoses. I’m not sure if each of these was done to address the issue, specifically, or if they were done simply as some sort of maintenance. Either way, these repairs did not solve the problem. My car would still overheat.
The second set of repairs was done 9 months later. This time I had the coolant fan switch replaced. This seemed to fix the problem. My car didn’t overheat for nearly a year. Well, a few weeks ago, it began overheating again, and so I took it to a different mechanic.
The third, and most recent, set of repairs involved replacing the entire fan motor unit, the fan switch, and the thermostat (again). These mechanics said that although they weren’t sure what the problem was or how to reproduce it, the repairs they made should fix the problem. They didn’t. The car overheated on the way back.
Other Notes:
The coolant level has always remained stable throughout this ordeal.
The radiator has never appeared to malfunction (after speaking with the mechanics about overheating, some suggested feeling if the radiator had any cold spots between the fins. Mine did not. Nor has any mechanic felt that this problem lay with my radiator or engine…granted, they had no idea what the problem was, I just felt that I should point this out, for what it’s worth).
The oil has always remained the same color (the color of oil – not milky or grimy); however, after the car overheats, the oil level tends to drop slightly. The car is not leaking oil, however – or at least that I can tell. There have been no oil stains, residue, or drops underneath my car noticed by me or any of the mechanics I have used.
The car can produce a smell when overheating. Usually it smells sort of metallic. The mechanics I’ve used said this smell was boiling coolant.
After taking the car home from the mechanic, it overheated again. I pulled over to look at the engine. I noticed neither fan was on. I turned the heater on, then both fans switched on. I turned the heater off, then both fans switched off. I turned the air conditioner on, then the driver’s-side fan switched on. I turned the air conditioner off, then the driver’s side fan switched off. The same happened when I turned the fan on and off (the coolest setting without using the air conditioner). I then turned the heater back on, but this time only the driver’s side fan would turn on. I’m not sure if this is what happens each time my car overheats, but I did notice it today and have noticed that my fans weren’t on upon prior occurrences of overheating.
Last edited by ts87; 09-13-2010 at 01:30 AM.
#2
Registered!!
iTrader: (11)
Join Date: Nov 2003
Location: Lakewood, 562
Age: 41
Posts: 4,576
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 295 Re: Engine Overheating Mystery
did you change your water pump? usually your suppose to change your water pump with the timing belt? could just be a dying water pump, i would double check the fan and thermostat since there a lot cheaper to fix first.
#5
Registered!!
iTrader: (2)
Join Date: Apr 2007
Location: New York
Posts: 2,018
Likes: 0
Received 2 Likes
on
2 Posts
Rep Power: 228 Re: Engine Overheating Mystery
Get your coolant tested for emission gasses in your coolant.
Replace your thermostat.
Check your upper radiator hose and make sure its hard when the car is at operating temperature, if not replace your radiator cap.
Do your fans come on?
Replace your thermostat.
Check your upper radiator hose and make sure its hard when the car is at operating temperature, if not replace your radiator cap.
Do your fans come on?
#6
Registered!!
iTrader: (1)
Join Date: Apr 2006
Location: nova & richmond VA
Age: 40
Posts: 825
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 251 Re: Engine Overheating Mystery
It's your head gasket not the water pump or thermostat if those went bad your car would overheat a lot faster then you are describing. I would first bleed the coolant system cause you probably have an air bubble in the line once that is out it should stop overheating if it continues then it is definitely a head gasket and it is pushing air into your system
#7
Registered!!
iTrader: (2)
Join Date: Apr 2007
Location: New York
Posts: 2,018
Likes: 0
Received 2 Likes
on
2 Posts
Rep Power: 228 Re: Engine Overheating Mystery
I agree make sure you dont have any air pockets in the system. Put your car nose up and then take off the radiator cap with the heat on and add coolant until its full
#8
Registered!!
Join Date: May 2009
Location: new iberia, louisiana
Posts: 74
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Engine Overheating Mystery
i had the same problem with my civic. it would go from in the middle of c and hott and would slowly climb when i was stoped and when i would go down the road it would start to go down then up a little. and when i was at a drive thru it would spike hott.it would get so hott that the thin hose that went from the top of the radiator to the return bottle would pressure up and blow the hose completly off. all i did to fix the problem is i changed the radiator and the hoses and added new antifreeze and my problem was solved.
#9
Registered!!
iTrader: (1)
Join Date: Apr 2006
Location: nova & richmond VA
Age: 40
Posts: 825
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 251 Re: Engine Overheating Mystery
The car does not need to be nose up in fact it is better if the car is level if it is up you can still get air stuck in little cavities.
to bleed the system: undo the radiator cap with the car cold. start the car up and wait sit there with a pitcher of water watching it. if there is nothing wrong with your system the coolant will just sit there if there is air it will push coolant out of the were the radiator cap goes if it pushes any out just fill it up with some water keep doing this till it stops it can take up to a half an hour to do this. If it just doesn't stop that head gasket is fried and you need to change it quick.
usually when head gaskets start to go the only push air into the system at the higher rpms at first cause their is more pressure at the high rpms eventually it gets worse and worse till it just pushes air all the time.
#10
Registered!!
iTrader: (1)
Join Date: Apr 2006
Location: nova & richmond VA
Age: 40
Posts: 825
Likes: 0
Received 1 Like
on
1 Post
Rep Power: 251 Re: Engine Overheating Mystery
i had the same problem with my civic. it would go from in the middle of c and hott and would slowly climb when i was stoped and when i would go down the road it would start to go down then up a little. and when i was at a drive thru it would spike hott.it would get so hott that the thin hose that went from the top of the radiator to the return bottle would pressure up and blow the hose completly off. all i did to fix the problem is i changed the radiator and the hoses and added new antifreeze and my problem was solved.
#11
Re: Engine Overheating Mystery
It still could be your head gasket. Sometimes headgaskets will crack and leak into the exhaust port. Which might or might not be the problem. Just smell your exhaust fumes. If the fumes smell sweet, go get it checked out. If not. Its more then likly one of the simple solutions above.
#12
Registered!!
iTrader: (2)
Join Date: Apr 2007
Location: New York
Posts: 2,018
Likes: 0
Received 2 Likes
on
2 Posts
Rep Power: 228 Re: Engine Overheating Mystery
What?
The car does not need to be nose up in fact it is better if the car is level if it is up you can still get air stuck in little cavities.
to bleed the system: undo the radiator cap with the car cold. start the car up and wait sit there with a pitcher of water watching it. if there is nothing wrong with your system the coolant will just sit there if there is air it will push coolant out of the were the radiator cap goes if it pushes any out just fill it up with some water keep doing this till it stops it can take up to a half an hour to do this. If it just doesn't stop that head gasket is fried and you need to change it quick.
usually when head gaskets start to go the only push air into the system at the higher rpms at first cause their is more pressure at the high rpms eventually it gets worse and worse till it just pushes air all the time.
The car does not need to be nose up in fact it is better if the car is level if it is up you can still get air stuck in little cavities.
to bleed the system: undo the radiator cap with the car cold. start the car up and wait sit there with a pitcher of water watching it. if there is nothing wrong with your system the coolant will just sit there if there is air it will push coolant out of the were the radiator cap goes if it pushes any out just fill it up with some water keep doing this till it stops it can take up to a half an hour to do this. If it just doesn't stop that head gasket is fried and you need to change it quick.
usually when head gaskets start to go the only push air into the system at the higher rpms at first cause their is more pressure at the high rpms eventually it gets worse and worse till it just pushes air all the time.
#13
Registered!!
Join Date: May 2009
Location: new iberia, louisiana
Posts: 74
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Engine Overheating Mystery
thats kinda what it was. i never changed it since i had got the car and i guess it got clogged somewhere. i had got a radiator off of my friends wrecked 05 civic. it was off a automatic and i have a 5 speed so i had to not use the lines that the oil lines went to on the bottom so i used the hose to cap them off and the car runs fine.
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
Xuhme
Cracked block early R18 Overheating
21
08-07-2023 03:40 PM
thana
Overheating or loss of coolant, heater blowing cold
11
06-15-2020 07:05 PM
blazebrown
Overheating or loss of coolant, heater blowing cold
18
06-02-2019 12:31 PM
zaboomafoozarg
Mechanical Problems/Vehicle Issues and Fix-it Forum
13
05-30-2015 09:21 AM
deus-ex
Mechanical Problems/Vehicle Issues and Fix-it Forum
2
04-13-2015 12:29 PM