Hope someone can help. I have a 98 Civic DX and sometimes if I take a drive for over an hour it will heat up when I get off the highway. There are no signs of fluid leaking from the radiator / no white smoke coming out of exaust. No milky oil from cap or dip stick. The coolant overflows into the reserve and sometimes I need to pour it back into the radiator and then the car is fine. If it does heat up I never let it go close to 3/4 on the temp.

What makes it a mystery is because I can drive a few hours and its fine. It doe's not do it all the time. It makes no sense. One thing I do remember and this might be the issue, my radiator cracked a year ago and it didn't over heat. I caught it when the car was parked. I bought a radiator from Advance Auto and this was when it all started.

The radiator has two metal prongs that come out the bottom for fluid or something but it's nothing for my civic. It's a universal radiator. Could it be that the radiator is two small or not right for the system???

I put a new thermostat in it and that is working fine.

I greatly appreciate any info. Please help and thank you.

John

 

welcome to the forum. Did you bleed all the air out from the bleed port near the thermostate area. Is the hose in good condition that it does not have a partial collapse to allow all the water as needed. Is the radiator cap in good condition to allow the water to recupe back from the resovoir back into the radiator. You should not have to refill the radiator, except during normal servicing. is the rad fan working properly when it gets warm. the two tips at the bottom of the rad is for automatic trans cooling.

 

I agree with acmech,the only thing I can add is check your fuses to make sure the fan relay fuse is not blown.Good luck,Bobby

 

Thank you Acmech. No, did not bleed the air out and I replaced the rad cap twice. The first time I replaced it the car was back to normal. It started doing it again maybe a few months later. I got another rad cap but still doe's the same thing.

I did forget to mention and thanks for reminding me, the fan was not working properly. I just replaced the fan relay switch about 3 weeks ago. When I bought the relay switch I took a 15 minute drive home I let the car run in the driveway and let it heat up to see if the fan would run. The fan came on and stayed on and the needle did not go over half way.

I thought it was prob a fan problem because 4 weeks ago I was on a 2 hour drive and when I got off the highway the needle went to half way and I pulled over. I turned the car on without cranking the engine and the fan did not go on. The next day I took another 2 hr drive and the car was fine. Later that evening driving home I stopped for fast food and it started to heat up. I pulled over and turned the car on without cranking the engine and I could hear and feel the fan come on. That is when I replaced the relay switch the next day.

It still heated up with the new relay switch in. The antifreeze is being forced (overflowing to top) into the reserve and there is no fluid in the radiator. If I leave the radiator empty it heats up. If I pour some back in it cools down and the car is good.

I needed to replace the hoses a few times because the first hose's I bought from advance did not snug on. They had some play to them and had to get new hose's a little smaller. I went to get a rad cap from Honda but they asked where I got the new rad from and I said Advance and they said to get the rad cap from them. I was wondering if I should just get a new rad from Honda with there hose's and cap??

Let me know what you suggest and I appreciate your time and knowledge.

Thanks
John

 

take a compression check, also check to see if there is high bypass into your rad-- while cool/cold open rad cap, make sure it is full of fluid, run your engine and see if there is a lot of bubbles coming out. Do not stick your face above the opening, it may shoot up water into your face. If lots of bubbles, you may have a head gasket leaking compression into your cooling system causing the water to all come out of the rad.

 

Thank you Acmech. I will need to take it somewhere to get a comp test. I ran it cool with rad full and no bubbles at all.

Thank you
John

 

ok well it seams like your car is overheating only when you are driving a distance and are at a standstill which tells me you are having issues with your fan. when your are at a stand still your fans are supposed to be working cause moving air moves thru the radiator coooling and at a stand still the fans are supposed to do the job of the moving air. you need to make sure you have a shroud on your radiator for your fan and your fans connections are good. i would disconnect the fans and jump it with a jump to make sure the fans work at all. if they do work then you know that your are not getting any power to your fans which means you have faulty wiring. you have changed everything else. the car cools down if you turn on the heater if the car is overheating correct?

 

Thanks Jaydawg for your time. It is a fan problem. The fan is not going on when the car starts to heat up. The Ac fan is fine just the radiator. I've never jumped it before and not sure what you mean ? Is there any way to test this myself ? and if so, what connections do I test ?

Thanks John

 

Again

 

And Again Buckwheat. The relay switch was replaced and fan is still not working right.