I have a 93 Accord that is overheating. The car will overheat when I am driving down the highway at 70mph when it is 20 degrees out, but not everytime. It will overheat now and then when I am at an idle sitting in traffic. The fans work sometimes when they are suppose to and sometimes not, also I have grabbed the bottom hose when the gauge is up close to the red and the hose is cool. I replaced the thermostat because of the bottom hose being cool, but it did not help it. I replaced the fan switch and it seem so come on more often, but still not always when it is suppose to. Also, the radiator, radiator cap, and water pump has been replaced in the past 20K. I dread the worst, the head gasket, but wanted to know if anyone had any other ideas before I dive into that project. I do not see antifreeze dripping externally, in the oil, or air bubbles coming up through the radiator. Any suggestion appreciated.

 

Good luck man.. Maybe we can figure this one out..

I have the same problem.. same symptoms on a 40k mile JDM motor.. The motor would over heat with NO thermostat in it and the fans would not kick on untill you turned it off.. the fan switch on the thermostat housing tests okay, I even tried another known good one. I always had the problem ever since the swap.. and the old motor that blew up had never had an over heating problem.

In an attemp to solve the problem, I had installed a new head gasket, new thermostat, bleed and flushed the system god knows how many times. Now that it's cold out I had to put the thermostat back in. Now it runs just above the normal operating temperature, but it will still creep up and overheat on me and there would still be no heat in the car. I also noticed that sitting ther idling the temp on the car will stay normal, but when I revv it up the temp guage will sky rocket and then eventually drop slowly again.

I had installed the motor myself after purchasing the JDM, it had come with a warranty and would have been covered, but I did not have money/time to remove it myself again. At the time I had changed the timing belt, and the silent shaft belt, I had assumed the waterpump to be fine during the installation of the motor, but for the 40 bucks, I should have changed it anyway. I seriously think that it's the waterpump in the car that is bad or an actual blockeage in the system.

One thing I see though is when the car warms up with the radiator cap off.. the fluid level will move up and down.. but the car heats up fast and it almost seems like the coolant is boiling.. but you don't actually see little bubble come out as if it had a cracked block or blown head gasket.

So yeah, I need to figure out this bastard.. I've been driving it in it's current status and put almost 12k on it in the past 5 months, the problem doesn't seem to get any worse.

What do you think? clogged cooling system? to add another twist.. when I received the motor.. you could tell they had run the car for a little while with plain water in the cooling system (or bad coolant) and the motor I got also did not have a thermostat installed.. so it definetly had this problem prior to being removed from the japanese car. The motor runs great on the other hand.. quiet.. starts right up, great power, high revving, over 30mpg

What do you think? maybe we can figure this out.. my car is in my sig.. same motor as you have.

Brendan.

 

if the lower radiator hose is cool when engine temp is hot it sounds like you got a t-stat sticking close....you might have a partialy working t-stat,,,,,,,,,did you install a honda t-stat when you replaced it ?? ...

 

Hondamatic -
you described my problem to a T. I thought it might be a head gasket since the fluid does move as you discribed when the cap is off, but it sounds like you tried that. I have a new water pump and I still have the problem. As far as a blockage I thought of that, but since all the hoses get hot (except the bottom gets warm sometimes) and I can get fluid out the bleeder I do am reluctant to say that. So I am still at a lose.

Deserthonda -
I have tried 2 thermostats (1 from NAPA and 1 from Autozone) because of the idea of a sticking thermostat. Is the Honda one that much different? I have never seen a difference between aftermarket and the dealers thermostat in the past.

 

i am going from past experience every single car i have worked on, when the lower radiator hose was considerably cooler than the upper hose, it turned out to be a bad t-stat,, ,If you suspect the head gasket, do a leakage test,, ... One last silly question,, you car is definately overheating right ?? you are not just going by the gauge reading right? I have seen a few gauges give false readings as well,,

 

It is definitely overheating. If I have the cap off it will start to bubble and if I am stuck in traffic I see steam from the front of the car.
I normally would think the stat is bad if the lower hose is cool, but since I have put 2 in I am stumbed. I will also do a leak test.

 

Hmm.. that's really interesting.. I have tried 2 NAPA thermostats.. and ended up putting the original one that was in the old motor. I never had any kind of overheating problem before I changed motors, I had installled a new radiator about 4k before the motor swap.

Has anyone ever put radiator stop-leak through your cooling system at all? I thought of maybe that was causing some sort of restriction in the cooling system if that junk was put in at soe point.

The engine itself looks brand new on the inside, I changed my oil at 5k miles(all highway) and it looked VERY clean, hardly different from when it went in. I can't imagine having a cracked blcok or something, this car has awesome power and great gas mileage.. I just wonder what gives?

Someone suggested it could be bad timing.. but I hooked up an advanced Snap-on timing light to it and I have it set perfectly.. I also have brand new iginition from the distributor itself all the way to the NGK Iridium plugs.

Cracked block maybe? I am just glad I'm not the only one with the problem, maybe it's something simple..

Do you have a problem where in cold weather, when you run your heat at idle.. it starts off warm but then will turn cold even though the car is fully warmed up.. and then when you press the gass and hold it for a little bit the hot air comes back really hot?

 

Deserthonds was right, it was the t-stat. I have put in 2 aftermarket t-stats and it did not fix the problem. I bought a Honda one and it worked. There are some differences with the aftermarket and the Honda one. While I was up at the dealer I ran into an old co worker and he said he sees aftermarket ones cause this problem all the time.

Thanks for all the help.

Hondamatic - I hope this works for you too, Good Luck.

 

Glad that it is fixed........... Happy New Year /////////

 

no way![:@]


Son of a..

You know how much time/money I invested in this junker? I better get my *** over to a honda dealer!

I'll let you know.. but intill then Have a good new years guys!

Brendan