genuwine4532

I have a 1989 Honda Accord that was overheating when going up high grade hills only and on long freeway trips, I was told the radiator is rotted out so I replaced it with a new one as well as two older hoses and I bled the air valve.

Everything seemed better for a couple of days, and then I went down the mountain as I live at 5,000 feet and drove around town for a while on flat land and it was fine, as soon as I began to go back up the mountain the car began to over heat again, I stopped and it cooled down quickly, but it continues to overheat only when going up hill and on very long freeway trips.

There is no white smoke coming out of the muffler
Oil is clean, no froth, or milkiness
Coolant is clean and bright green,
Car runs great, as always with power and drive.
I am not losing coolant regularly, but when it overheats I can see coolant sputtering from the top of the overflow tank, and then it stops, and once the car is cool, the overflow tank is fine and full of coolant.

Today the car started to get hot on the uphill again and I pulled over and when I opened the hood there was coolant sputtering out of the radiator cap for the first time throughout all this, I waited a little while and made sure the cap was tight and went home. The car stayed cool because I was on flat ground and when I got home the radiator cap seemed fine, the cap is a few months old and was the one I used with the old radiator.

1. I did not change the thermostat when I changed the radiator--should I have?
2. I did not buy a new cap for the new radiator, used the old one which was only a few months old, should I get a new one?
3. Also, the cooling system air bleeder valve, can it be stripped and releasing pressure? as I noticed today there was a drop of coolant on it after overheating and it should be sealed tight????

Help please, I do not know what to check and do next????

Thanks for your time.

Hondadude141

I would start with the cap and then from there, check the hose running to the coolant overflow tank and make sure that isn't clogged, and then make sure your heater hoses haven't cracked or anything just to be sure.

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genuwine4532

Thanks I will try that

Hondadude141

AND! haha I completely left out the thermostat, if all of that stuff I listed above does nothing then I would try replacing the thermostat, that could be the problem but I'd save it for last.

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genuwine4532

LOL, I was wondering what happened to the therm, thanks again

Hondadude141

no problem!

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JDMchic

The same thing happened to my Accord last night...although I wasn't driving up hill. Basically I pulled into my friends driveway, which is inclined up, and left the car running. I about 5 mins the car was overheating and anti-freeze was bubbling out of the radiator reserve cap. Checked everywhere, no loose/cracked hoses.....still have no idea why it overheated. Only issue that triggered it was the upward incline.....did u ever find out the problem???

f22b1 coupe

ALmost definitely the radiator cap if it's boiling over like that- first the cap allows coolant to escape, then the lack of coolant causes it to get hot. But make sure your fans are engaging, and replace the thermostat just in case that's it.