Rep Power: 0

i need som help here guys. i searched around but would like some opinions as well. My 03 ex started overheating last week pretty badly. Mostly in stop and go traffic. I checked my coolant level and it was a little low. I filled it up and everything seemed fine. This morning it overheats again and i check under the hood. My reservoir tank was almost full and there was coolant spewed across some of the engine. I don't think its a leak but i don't understand why its spewing out of the reservoir... On top of it all, i read about the air bubbles so i tried to get them out but the coolant starts spilling out of the neck almost immediataly. Also, my freakin heater doesn't work at all! I am very confused and need some tips asap.

 
Rep Power: 0

Your thermostat is stuck in the closed position. That would explain both the overheating and no heat. Replace it with a new one and a thermostat gasket and you will be back to normal. The thermostat isn't allowing coolant to flow all so it is boiling over due to the lack of circulation through to the radiator. It also won't flow to your heater core, so you have no heat.

 
Rep Power: 295

whew, thats a relief, mine is doing the same thing (03 LX coupe 5 sp) I though FOR SURE that it was a blown headgasket... I HOPE its just the thermostat!

 
Rep Power: 323

sounds like a head gasket, but it would not hurt to try replacing the thermostat first.

 
Rep Power: 0

If you allow it to overheat, it will eventually warp the head gasket sealing surfaces and you will then require a headgasket replacement.

 
Rep Power: 0

So i took my car to Honda. They replaced the radiator under warranty and the car seemed fine for a few days. Then today it starts overheating again. Not as bad as before but still a little past the middle. Both my raidiator hoses are hot and stiff. However, there is coolant spewed on some parts of the engine. I think its coming from the reservoir but i dont know why. My heat blows cold air at idle also. It only overheats in stop n go traffic. help pleeeeese.

 
Rep Power: 453

Have you replaced the thermostat as tacheon suggested?

 
Rep Power: 0

Yeah it was replaced with the radiator. I also forgot to mention that the fans work fine.

 
Rep Power: 0

I'd be looking for a head gasket leak at this point. With the engine cold, start the car with the radiator cap off. See if bubbles come out. If bubbles come out immediately, then you likely have a head gasket leak. You can also do a compression test on all the cylinder to confirm the findings.

 
Rep Power: 812

i hope the dealer bled the air bubbles out cause when I had bubbles in mine, my heater wouldn't work either. Compression test is good advice I would try that to see for sure.

 
Rep Power: 0

ok, so i understand the air bubbles would mess up the heater, but would that justify the car overheating?

 
Rep Power: 812

yes, air does not cool nearly as well as liquid.

 
Rep Power: 0

i see, thanks for the info. i also heard that if the hg is leaking, the car would overheat on the highway as well. mine only overheats at idle or stop n go. is this true?

 
Rep Power: 812

i'm not sure, but the head gasket should be the last thing you check. air bubbles definately lower the cooling ability.

 
Rep Power: 0

Head gasket leak can also occur as the car heats up. The gap in the headgasket can expand allowing combustion gases into the coolant.

 
Rep Power: 302

Air bubbles trapped in the cylinder head is a common issue with Hondas. If Honda replaced the radiator but the stooge in the service bay didn't properly bleed the system with the heater on HIGH, the problem will NOT go away. You MUST get all the residual air out of the system.

 
Rep Power: 0

can someone tell me exactly how to properly bleed the air out?

 
Rep Power: 0

also, when the car is cold and i open the radiator cap, the coolant is nowhere to be seen. Is it supposed to be full to the neck when the car is cool? it also seems like it keeps backing into the goddam reservoir and spews out the top when the car gets hot.

 
Rep Power: 812

When the car is cold, open the radiator cap and turn car on. Press the gas lightly to warm up the car to operating temp. Once at temp, turn the heater on full blast and watch the coolant in the radiator. As bubbles pop, add coolant to keep the level up. Its okay if some overflows while doing this. Keep doing it until bubbles stop. You should also turn on the a/c so the fans come on. I believe this is responsible for changing coolant flow but can't remember how. But you should see more air bubbles. Rev the engine a bit every so often. You can use the throttle lever instead of gas pedal. Once you don't see bubbles coming up, turn off the car and replace the coolant cap. Also while you're doing the heater part, eventually the heater should get very hot like before as the air escapes.

 
Rep Power: 812

the coolant should be filled to the top of the radiator when you first open the cap (when car is cold).

 
Rep Power: 453

I see we posted at the same time so I deleted mine. SO do as gearbox said.

 
Rep Power: 0

I think there's something more serious than air in the cooling system here. It would have been filled properly during the radiator and thermostat change.

 
Rep Power: 0

ok heres the latest update: i did the procedure for getting the air bubbles out and everything seemed fine. But after long trips where the engine gets fairly hot, a problem arises.... the coolant flows into the reserve tank nonstop until it starts spewing out the top and doesn't go back into the radiator. WTF???

 
Rep Power: 0

Got a few questions for you. Are your fans on at full speed at the time they are spewing out coolant? Do you have heater put out heat? Does the temperature gauge show the car is overheating? I'm convinced it is definitely not an air bubble problem. Your answers to these will bring us closer to solving the problem.

 
Rep Power: 0

Yes the fans work and the car overheats even when they are working. The heater has been putting out heat lately but when too much coolant spews out the top of the reserve, the heater becomes less effective and eventually puts out cold air. I top off the coolant every couple of days. and yes the temp gauge shows the car overheating, it rises until i start driving hard and it goes back down. Im taking it in to the dealer tomorrow.

 
Rep Power: 319

weird....

Does the car yak coolant when the heater is off or on, or whenever?

 
Rep Power: 0

only when its driven for a while. usually happens when i take long highway trips (10-20 minutes) then when i get into stop n go traffic, it starts.

 
Rep Power: 319

humm..... yeah... I'm leaning towards a blown gasket or something along those lines. I would do a compression check ASAP to see if any cylinders are leaking. Let me dig around in my Integra Helm's and see if can find something about that, I don't think the system has changed much over the years.

 
Rep Power: 319

Just out of curisity, what does you oil looks like? If you have coolant in it should have thick white flakes in it and look kind of like a milkshake. Any white smoke (sweet smell come out of the back of your car when you start or anything like that? If yes to anyof these, turn your car off and don't start it until the problem is fixed.

 
Rep Power: 453

I found this on another site while doing some searching to help you and as this describes, sounds as if your head gasket is blown.

"There are any number of things that'll happen when your blow a head gasket.

Common symptoms:
- Foaming, bubbling, or "gargling" in the radiator.
- Rapid pressure buildup in your cooling system, before the engine has warmed up.
- Some have even reported coolant overflowing from the reservoir bottle because of the pressure.

All these above mentioned symptoms could also be a cracked head. Either way, the head must come off, the gasket replaced, and the head inspected for cracks. At the same time, check both mating surfaces for flatness before putting on a new gasket so you don't have to repeat the job.

Other symptoms of a blown head gasket include:
- White smoke coming from the tailpipe, sometimes intermittently.
- Water in the oil. When they mix, the oil gets a chocolate milkshake appearance.
- Oil in the coolant.
- Cylinder pressure low when using either the wet or dry compression method.
- Cooling system will not hold pressure when statically pressurized.

Look for any combination of these symptoms to diagnose a bad head gasket.

One curious observation of mine, when a person describes their engine problems, and it looks like a blown head gasket, often they mention that the car just had a new radiator put in, or new cooling fan, or some other repair history that suggests the car was constantly overheating.

If you had white smoke coming from the tailpipe and your head gasket was bad, chances are the O2 sensor may have been poisoned at the same time. Expect to have problems with it. It may need to be replaced.

Footnote:

One of the bigger challenges for the engineer is to design a head gasket that'll seal the aluminum head to the cast iron block. Aluminum has roughly three times the thermal expansion characteristics of iron. That makes it tougher for the head gasket to maintain a seal with all that thermal cycling than in years past with iron heads. Aluminum heads cannot withstand overheating as iron heads could in the past. It is critical to not let your engine overheat. Overheating is the No. 1 cause of scrapping an engine, not oil neglect as some people believe. Even if you don't blow a head gasket, the head may warp and cause premature wear on the valvetrain components as in some early 4-cylinder Mopar engines from the early 80s"

I think the article was talking about crysler vehicles, but should be the same for any vehicle