Engine Overheating

1997 HONDA ACCORD
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GOLDENTRAIL
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Recently, i had an overheating problem. When i was driving, i noticed that the temperature is rising and going to the red zone. So i stopped and opened the hood while the engine is still running. I noticed that the radiator fan is not running even when the engine is so hot at that time. I turned the AC on and both the AC fan and radiator fan turned on. But making the fans turn on at that time could no longer lower down the temperature which was already above the middle mark of the gauge. Turning the AC off also turned both fans off. So i shut off the engine to let it cool down. When it was cooled down, i opened the radiator cap and found the level of coolant ok, so i discounted any possible leaks. I called a friend and was advised to check for the thermostat. But i dont know where the thermostat is located. is it the one connected to the upper radiator hose or the one connected to the lower radiator hose at the engine side? i also noticed that the upper radiator hose is too hot while the lower radiator hose is not hot or is just warm maybe. is it possible that the water is not circulating? what could be the problem why the fan is not automatically turning on when the engine is hot? please advise. thanks.
Mar 20, 2008 at 8:14 AM
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MERLIN2021
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Mounted on the thermostat housing, which is at the end of the upper radiator hose, find the fan switch, test it and the relay in the underhood fuse box...If the fans work when a/c comes on it will most likely be the switch on t stat housing!

Check out this guide

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Mar 20, 2008 at 8:34 AM
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GOLDENTRAIL
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I tested the switch located in the upper radiator hose and shorted the terminals using a paper clip, but the fan didnt work. but when i detached and shorted the switch located at the lower radiator hose which is at the engine side, both the fans (AC and radiator fans) turned on. So what is that switch that made both the AC and radiator fans turn on? I am really confused if which is really the thermostat housing, is it the one on the lower radiator hose or the one on the upper radiator hose? I would also like to know how to test if the water/coolant in the cooling system is circulating or not. This is because i noticed that the upper radiator hose is too hot while the lower radiator hose is cold, so i presumed that the water is not circulating in the system. Inserted a picture here showing the connections. The lower portion of the picture with the green switch is the upper radiator hose connection, while the upper portion of the picture with another green switch is the lower radiator hose connection to the engine. Thanks.


https://www.2carpros.com/forum/automotive_pictures/170607_055_1.jpg

Mar 20, 2008 at 7:24 PM
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MERLIN2021
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My mistake the one on the lower hose has the thermostat! In your case you may have a stuck thermostat, that will be the firest thing to change...if the water is cold at that lower hose, the switch will not turn on the fans! Flush and fill the cooling system while your at it. If after replacing the tstat, the fans don't work, replace the switch...
Mar 21, 2008 at 6:00 AM
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GOLDENTRAIL
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Thank you. I will try that. My problem now is how to remove the thermostat housing considering the many wirings and the big hose that are blocking it. Thanks again.
Mar 21, 2008 at 7:17 PM
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JERSEYGRL1
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Thanks in advance for your help!

I have a 1997 Honda Accord LX (4cylinder)and it continues to overheat, although it's had major updates over the last 4 weeks.

Here is what has been changed out so far:
-radiator
-thermostat
-temp sensor
-catalytic converter
-1 fan (but neither are firing up and the relays have been checked and appear good)
-plugs & wires(for a different issue)

The weird issue seems to be that when I start the car and leave it in park, it can set for 15 or more minutes with the temperature staying where it always has. Slip into drive and the temperature starts to rise and pegs out in a mile or so.

Dec 17, 2019 at 5:31 PM (Merged)
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ASEMASTER6371
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first of all, the fact that it pegged means to me that you had driven it overheated and most likely caused a head gasket to fail. you need a shop now that will do a leak down test to confirm. hopefully, the head is not cracked but if the gasket is blown, it would explain a lot of your concerns.
if the gasket is good, i would look at the water pump as it may not be circulating the water at the proper rate.
as far as the fans, that may have been the original issue that caused all this. signals from the ect sensor, relays and the fan motor itself are the components in the system.
by the way, did the fans come on when the ac was turned on??
Roy
Dec 17, 2019 at 5:31 PM (Merged)
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JERSEYGRL1
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Thanks so much Roy! We'll get it in to have that leak test done right away.

As for the fans, when the car was purchased we thought both fans were working, but later found that only one was, so the other was replaced. However, now neither come on, even when the AC is turned on.
Dec 17, 2019 at 5:31 PM (Merged)
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ASEMASTER6371
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with air in the system, they will not work, the air may be the result of the head gasket. take one step at a time.

Roy
Dec 17, 2019 at 5:31 PM (Merged)
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JERSEYGRL1
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Will do and thanks again. Will post the results.
Dec 17, 2019 at 5:31 PM (Merged)
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ASEMASTER6371
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good luck

Roy
Dec 17, 2019 at 5:31 PM (Merged)
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LAURA COMEGYS
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So i bought my car in February 2016 its now November 2016 my car kept overheating so i decided to change the thermostat just to find out there was no thermostat inside. After replacing the thermostat the car began to over heat to where i had to refill the radiator two to three times a day with coolant my car is still over heating, but nothing leaks from the radiator everything over flows out of the overt flow tank. what could be wrong?
Dec 17, 2019 at 5:31 PM (Merged)
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MHPAUTOS
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You may have a blocked radiator causing little or redistricted flow. have the radiator removed and core cleaned start here.
Dec 17, 2019 at 5:31 PM (Merged)
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STANBASE
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want to know what causes periodic overheating of engine.
Dec 17, 2019 at 5:31 PM (Merged)
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CARADIODOC
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Need a better list of clues and observations than "periodic". Does this occur at highway speed? Slow, city driving? Any smoke out the tail pipe? If so, is it white? Are you having to add coolant or has the level dropped? Can you hear if the radiator fan turns on? When the overheating occurs, can you get really hot air from the heater or is it cold? Does running the heater bring the engine temperature down?
Dec 17, 2019 at 5:31 PM (Merged)
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STANBASE
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hi
thanks for the answer. will observe all listed occurrences.
Dec 17, 2019 at 5:31 PM (Merged)
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MEJIA55
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I have a 97 accord which has that problem. it overheated once and found out that it was the gasket. So ive had the gasket repaired timing belt water pump o2 sensors idle air temp sensors distributor etc. The car still runs fine but at times when driving prolonged amounts of time recently my needle goes up to the middle in the temperature gauge and last sunday it went up above the middle but not close to the red. So my question is what can it be since my mechanic drove it the other day in 110 degree weather for 45 mins straight and no overheating occurred. no oil leaks through the spark plugs or any of the sort. what do you think can be the problem?
Dec 17, 2019 at 5:32 PM (Merged)
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RASMATAZ
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1st thing I'll do-is remove the thermostat and see what happens-if it gets cooler replace it- If not get the cooling system block and pressure tested.
Dec 17, 2019 at 5:32 PM (Merged)
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CHIZZY77
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I just purchased a 1997 honda accord and after a week it started running hot. When I open the hood i can see and hear steam coming out of the reserve coolant tank. i took it to a mechanic and he half-way looked at the car then explained that I need a new engine. He told me that my head gasket is bad on the pressure side. I dont have any money to buy a new engine. I dont want to believe that is the problem. I need a second opinion.
Dec 17, 2019 at 5:32 PM (Merged)
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BLUELIGHTNIN6
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even if it was a failed head gasket that would not call for a new motor... you will need to have a compression test done to see if the head gasket is indeed faulty though.
Dec 17, 2019 at 5:32 PM (Merged)
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FANMAN9707
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I had a thermostat go bad and did not catch it in time so I ended up with a cracked radiator. I changed the thermostat and the radiator and it stayed cool for a month or more now it is overheating again. The thermostat is working both of the hoses to it are warm, but the overflow is hissing and spraying hot water out of it. Is it possible putting to much water in the radiator and the resevior could somehow make it overheat? Or a clog possibly? When we reconnected the bottom hose we had to bend it just a little more than it was to get it to go on. I'm thinking this may also be the problem. Any other ideas would be greatly appreciated. Thank You
Dec 17, 2019 at 5:32 PM (Merged)
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MFISH98
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Well it is very possible that when the motor overheated previously the head gasket was weakened... And now you may be building up air in the system because of the head gasket. A clog can also cause the problem, but if both hoses are hot it sounds more likely that it is a head gasket.
Dec 17, 2019 at 5:32 PM (Merged)
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FANMAN9707
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Is there anyway to test that? Changing the head gasket carries a pretty hefty price. Also if was the head gasket wouldn't it overheat pretty fast and run poorly with a loss in mpg. My car seems to run fine and the needle takes it's sweet time to make it's way past the halfway mark on the gauge. It also stays perfectly cool when driving. Temp doesn't start to rise unless you are parked for a few minutes.
Dec 17, 2019 at 5:32 PM (Merged)
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MFISH98
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Yes you are right in saying it would overheat quickly. And it depends on the severity of the blown gasket as to how it would perform. Sometimes you will get white smoke from the tail pipe. But in your case, since you mentioned that it doesn't overheat when you are moving makes me think about the cooling fan. Is it working? You might let it run at an idle for a little bit (paying attention to how hot it gets) and see if the fan ever kicks on.
Dec 17, 2019 at 5:32 PM (Merged)
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FANMAN9707
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Yes the fans seem to be working fine. Yesterday when I noticed the needle start to move I heard the fans come on. The fans would also cause a check engine light to appear would they not?
Dec 17, 2019 at 5:32 PM (Merged)
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MFISH98
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I'm not sure that the fans would trip the check engine light. But something you can check now is while it is getting hot try and squeeze the radiator hoses. (wear some gloves or use a rag as it will be warm/hot) But what I want you to look for is whether or not the hose feels solid. (like it has pressure built up, and check it after the thermostat has opened.)

Also, your problems could be caused by a bad radiator cap if you have not already replaced it.
Dec 17, 2019 at 5:32 PM (Merged)
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HOFF9060
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Car overheats at idle. Dumps coolant out of overflow. It has a new thermostat, and radiator. No visible leaks on any hoses. Holds pressure on tester at 11 lbs. No oil in coolant and no coolant in oil. If the a/c is running it appears to make no difference in slowing or speeding up the overheating. Car runs fine. No rough idle. Great on gas. Both fans run and operate properly. Drives fine for daily use, then may overheat unexpectedly. Pours coolant from overflow. Sometimes overflow dumps out when vehicle is at normal operating temperature. I am stumped.
Dec 17, 2019 at 5:32 PM (Merged)
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FANMAN9707
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I will try the hose trick and the bad radiator cap could very well be a possibility. When I got the radiator, the cap would not go on and we had to slightly bend it to get it on. I will try these things and let you know the results. Thank You
Dec 17, 2019 at 5:32 PM (Merged)
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KHLOW2008
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Is the radiator cap new and of the correct specification?
Dec 17, 2019 at 5:32 PM (Merged)
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JOEY2234
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I have almost the same exact problem, exact same car..I recently replaced my radiator which was leaking due to a chunk of ice that was hit. After replacing that the radiator cap didnt fully fit all that well, but still went on. When I am driving my car it NEVER overheats. It will overheat if I leave it idling for about 5-10minutes or if i sit in traffic long enough. It doesnt overheat all that quick and when it overheats, it spits fluid out of the reservoir tank.

I am going to replace the cap today if you find a solution please let me know as it would be so helpful.
Dec 17, 2019 at 5:32 PM (Merged)
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HOFF9060
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Radiator cap is new. Just bought the car and it looked like it had overheated previously. I replaced the cap. I can not tell if it seals 100% though.
Dec 17, 2019 at 5:32 PM (Merged)
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FANMAN9707
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Let me know if the radiator cap fixes the problem. I am going to flush mine first and see what happens. Thx
Dec 17, 2019 at 5:32 PM (Merged)
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KHLOW2008
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If everything is working correctly, you might have a bad water pump. Sometimes the water pump impeller wears out.
Dec 17, 2019 at 5:32 PM (Merged)
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FANMAN9707
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I think I figured it out. The guy at Advance told me to take the radiator cap off and let the car idle til it starts to get hot and the radiator fluid should start bubbling out of the radiator. Rev the engine a little if needed to raise the temp of the engine. When their are no more bubbles it should be fine. I was told when you change or drain a radiator you should do this to get any air out of the system. Good luck and I hope this helps
Dec 17, 2019 at 5:32 PM (Merged)
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HOFF9060
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Is there any way to test the impeller without removing the pump? It seems to run fine for a while. Normal operating temp, but as soon as I slow in city traffic, it hits past the red line and begins to dump coolant. I also noticed the fan runs for about 10 minutes after the car is shut off, even if it has been running at normal temp.
Dec 17, 2019 at 5:32 PM (Merged)
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KHLOW2008
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There are no proper way of testing the water pump. What you can do is start engine with radiator cap off and let it run for a while till the thermostat opens. Watch the radiator neck for coolant movement.
Dec 17, 2019 at 5:32 PM (Merged)
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RMAN73
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Engine Cooling problem
1997 Honda Accord 4 cyl Front Wheel Drive 177000 miles

My Honda still is over heating. I replaced the thermostat and still over heats. So I drained the radiator and put 50/50 coolant in it and it still is over heating while ideling and ac on kind of lost and don't really know where to look next I'm hoping it ain't the waterpump any help would be great Ty
Dec 17, 2019 at 5:32 PM (Merged)
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SATURNTECH9
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Is your cooling fan coming on?Also when your a/c is on does your cooling fan run?
Dec 17, 2019 at 5:32 PM (Merged)
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HOFF9060
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The pump seems to be working. Water definitely flowing through the radiator. Everything seems to be in working order. After the car is at what appears to be operating temperature, I am able to remove the radiator cap and there does not seem to be any pressure release. I cannot tell if it seals properly from where the old cap had melted. If it won't hold pressure at the cap, could that cause the coolant reservoir to overflow and not draw coolant back into the radiator?
Dec 17, 2019 at 5:32 PM (Merged)
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RMAN73
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When ac is on they both run when they r off neither run
Dec 17, 2019 at 5:32 PM (Merged)
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KHLOW2008
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If it is not seated properly it would definitely cause problem. Check the depth of the radiator neck and the height of the radiator cap valve area.
Dec 17, 2019 at 5:32 PM (Merged)