Hi, I have a 2002 Honda Accord, 4 cylinder, 2.3 liter

I began to have an overheating problem one day last week. The first tech I took it to did a pressure check on my radiator and found leaks at the top and a faulty cap. So I replaced them.

Then, when I was driving at a good speed 45+, no over heating, but as soon as I started to idle, the temp gauge soared.

So I barely was able to get it off the road when this hit and unfortunately blew my head gasket. Another tech (the closest I could get to) replaced the gasket, the water pump, and the thermostat for safe measure (I'm about to drive 2400 miles across the desert and need the car to work).

I picked it up today and it happened again. I was fine on the freeway and as soon as I was off again, idling, I tried to turn up the a/c and that made the heat jump. I pulled off the road (I'm praying I didn't blow another gasket) and I'm having them take another look tomorrow.

Does any of this sound familiar? I am so perplexed and so is my mechanic. It seems to have something to do with the a/c - but when he lets it sit and idle w/ the a/c on the heating problem doesn't happen. It's only when I drive it on the freeway for 20+ minutes and then exit does this occur.

Obviously I've spent a stupid amount of money on the car so far, but it's only got 112k miles and it's never had a single problem before.

p.s. The personal stress of the situation is that I'm supposed to be starting a drive from Florida to LA tomorrow morning to start a new job next week and this is stopping me.

 

Did the mechanic have the cylinder head milled so it was perfectly flat before replacing the head gasket? Is the radiator still full of coolant? Check this by removing the radiator cap when the engine is cold.

Also, when you first start the car and turn on the a/c, do both fans on the radiator turn on? Have the mechanic pressure test the radiator again to see if the coolant system can hold pressure.

 

Suggest borrowing or buying a InfraRed temperature gun ( $25 at Harbor Freight) to measure temps when overheating is indicated. Perhaps the temp sensor has an internal short (this would drive gauge high very fast) that is causing the problem. If IR gun shows normal temps when gauge says high temp, then you've found the problem. Or just replace the temp sensor (perhaps cheaper solution than buying an IR gun).

good luck

 

So, last night I swear I spotted a coolant leak from the radiator, but today the mechanic said the system was full and the pressure test held up. They ran the car and said they saw smoke (first time it's done that), but can't figure out where there is a leak or what the problem is.

@pahonda, I'll ask about having the head milled. Both fans were running when I turned on the car, with a/c, too.

@texashonda, would this just mean that the gauge (in the car) is showing hot, but the temp inside the system would be fine? Well, the car is definitely overheating, not just faking it.

 

Not fully bleeding the air from cooling system can cause overheating. There is a bleeder valve on top of the intake manifold to allow air bleeding. Make sure this is checked.

Otherwise, a faulty head gasket installation seems likely.

good luck

 

Ok, so yesterday after overheating the night before and having the car towed to the mechanic, he could not reproduce the overheating. He pressure tested the radiator, found no leaks, and ran the car for hours with no problem. He was completely dumbfounded, but we took it as a miracle and hit the road. So far we've made it 1k miles and the car is doing alright. I have to say that @texashonda was probably right about bleeding the coolant - I've talked to several mechanics and Honda Accords of this decade are very prone to air bubbles in the coolant fluid. So if you have your radiator flushed, make sure to ask the mechanic to bleed the radiator afterward.

We are keeping our eyes on the gauge, though. From time to time it pushes up, but is settling back down around 40-45% on long drives.

The story that seems most likely at this point is that when the very first garage checked my levels, they removed the radiator cap which was old and faulty, which began a pressure problem in the radiator, and when I first overheated I probably stressed my head gasket which eventually ruptured due to age and wear.

We have another 1.4k miles to go before we hit LA, so fingers crossed. If anything changes, I will post more messages here.

Thanks, everybody!

 

Ha, spoke too soon!

Today we drove the car around town, and the heat gauge stayed down below half, but when I pulled into the driveway and had the car on an incline (not front-to-back, but side-to-side, with passenger side up) the gauge jumped and stayed there. I pulled the car into the garage, let it cool down, and checked the coolant levels and they were low. Can't find a leak, though.

Also, I noticed that my fans are coming on, but just for a moment here and there, and they don't stay on once the car has stopped. I seem to remember them running after I turned the car off when the car was newer.

Could a bad fan relay be the culprit?

 

When the car starts to overheat, turn on the heat inside the car and set the blower to the highest setting. You may be miserable, but your will help prevent damage to your engine due to high temps. I lost about ten pounds when my car started to overheat while stuck in a traffic jam in Chicago.

This could be a fan switch problem, because you said that both fans are running when the a/c is turned on. That means the relays are working properly, the fans may not be getting a signal to turn on.

There is one fan switch on the 98-02 accords. It is on the thermostat housing and is pretty simple to replace.

 

Do a pressure check on the coolant system. It will show the problem. Either it is a leak that will show up under-pressure for hoses, radiator, and if its a leak in the head gasket it will probably smoke or shut off the car engine.

 

Low coolant can cause both conditions: high temp at idle/on a slope and the fans going off and on erratically.

It's losing coolant but you can't find a leak, which leads me to suspect a head gasket. A leakdown test is in order. I don't know if you made it to LA yet but topping up the radiator with water at every gas stop should get you there. My car did exactly the same thing on a recent 1400 mile round trip through mountains and desert, and as long as I put water in it every 250 miles or so (it took about a quart each time) it ran fine/didn't overheat. The temp gauge would creep up towards the halfway mark on long climbs, but if would never go past halfway.

After a leak down test showed coolant being slowly pushed out out the radiator from three of the four cylinders, I replaced the head gasket, repeated the same 1400 mile trip, and didn't lose a drop of coolant. And the temp gauge never got near the halfway mark. The odd thing is that I couldn't find anything wrong after removing the head. The head was flat, the block was flat, and it had a Felpro gasket on it so it was replaced by a previous owner. The only thing I can think is that the head wasn't torqued correctly when the gasket was replaced. It's a three-step torque process so maybe mechanics get impatient and rush the job.