lalorm

Hi, my car overheats in a very uncommon way:

1. I changed thermostat. and keeps overheating.
2. I you turn on the car, and let it parked in idle it never overheats.
3. When you drive it and accelerating, it never over heats, but after driving for an hour or more, if i stop on a light it begins overheating, if I begin moving again it falls again to normal temp.
4. I also discovered that as i said, after driving for one hour, If i stop on a ligth the overheating begins. As I said the overheating goes away if I get moving, BUT also goes away if at the light with the transmission on parking I accelerate the car for 20 seconds at 2000 rpm.
5. So it seems that my car doesn't overheats if it is accelerating, no matter if you accelerate it on parking or on the freeway.
6. I dont think it could be my head gasket because I can drive the car for hours and never overheats if i don't stop.

I appreciate your help, I'm tired of not finding the answer.
Thanks

BlueEM2

iTrader: (1)

Your fans probably aren't turning on. I don't really understand what "accelerate it on parking" means but I'm assuming revving to 2000. Turn your AC on and see if the two fans mounted to the radiator are turning on. Do they come on when the car is overheating? If not your fan relay is shot and needs replacing.

lalorm

Hi, by "accelerate it on parking" I mean that if I'm still at the light, and I just accelerate the car for 20 seconds with the car stopped, the temp will go down. So I don't think it will be a fan problem, anyway I also tried connecting the fans permanently using a clip to close the circuit on fan thermo switch. but the result is the same.
Thanks

xRiCeBoYx

iTrader: (22)

so, if you rev up, is what you mean.

try flushing your coolant system?

02civicsi02

Ya do what riceboy said, flush the system cause I think you might got a air bubble in the system.

winggndm

More than likely your condenser fan is not turning on. Do this, turn on the AC compressor and check to see that the condenser fan does turn on. The fan is set to turn on when the A/C compressor clutch engages. So once you see the compressor engages, the fan has to turn on. If it does not check the fuse for the condenser fan. More than likely its blown. Why it blew is another question but more than likely the cycling of inrush current. Hope this helps.

GSmith215

I have an 03 Civic and am having the same exact problem. See my post below, I double posted by accident.

GSmith215

I have an 03 Civic and am having the same exact problem. The only things I can add are the following:

1- All my coolant ends up in my overflow tank (filled to the top) and my radiator ends up low (I have to add about 1/4 gallon to the radiator every few days).

2- Both fans cycle on and off when the A/C is on (and being in Florida, the A/C is on almost all the time). I don't know if the fan comes on without the A/C.

3- Yesterday, we had the car idling for about 25 minutes while waiting at a store (A/C on). The needle moved from just below dead center to dead center (didn't see how quickly, my wife was in the car) and then after I got in the car the needle moved up to slightly above center. I shut the car off for about 10 minutes, started it again. Drove it no more than 4 or 5 minutes at 35-50mph, pulled into another parking lot and ran into the drugstore with it idling with the A/C on. When I got back out (less than 5 minutes), the needle was pegged to the top.

I spoke to my Honda parts guy and he made the following suggestions:

1- The thermostat I put in after this problem started is defective (not opening all the way or not opening when it's supposed to).

2- The fan isn't coming on when it's supposed to with the A/C off (we drive the car with the A/C on almost all the time, and I can hear the fans cycling at idle, so I don't know if that's it.)

This has been going on for 23,000 miles, and I don't have a lot of $$ to fix this. Today I'm going to try running the car without the thermostat and see if I've got a major air pocket that I can't bleed out (yes, I've tried many times) and to see if the thermostat is the problem. I replaced the thermostat and radiator cap when I changed the lower radiator hose a few months ago (it was showing signs of dried fluids running down it, so I replaced the hose - the problem got slightly better with the new cap, themo and hose, but it didn't go away).

If you've had any luck (or if anyone else has any suggestions), please let me know.

GSmith215

Hey everyone,

So I just spent an hour trying to flush the air out of the cooling system. I removed the thermostat, hooked the hose back up, started the car with the radiator cap off and the heat turned to "on" but the A/C off.

1- The fans only came on *once* in almost 30 minutes of idling with the A/C off. Is that right? Once I turned the A/C on (about 30/40 minutes into this) the fans came on and stayed on.

2- It took me over 15 minutes of idling and adding coolant to get heat in the cabin. I'm sure there was air in the heater core, then.

3- The air bubbles do not stop. I cannot seem to get rid of them. The guy at the Honda part counter told me they use a special vented cap to purge the system of air so that it's under pressure but only letting air out. Anyone hear of that?

kvan

Hey guys,

Its my first post but I thought I will help you guys.

My car (02 civic lx 130k miles) did exactly the same thing in this thread. I've tried many things like a new radiator cap, new thermostat, new hoses, prestone super flush and a 80/20 mix of antifreeze to water.

None of those solutions worked.

The car had problems starting in the morning. It wouldn't start unless if you open the throttle.

I've taken the spark plugs out to see inside the cylinders and it had some pretty bad carbon deposits on the piston. Use a flash light to see inside.

I was really frustrated spending many hours trying to fix this.

I took it to my mechanic. He kept the car for 3 days until one of this techs reported coolant inside a cylinder.

They pulled off the head and checked it for straightness. There was a bulge in the middle. So they had to send it to a machine shop to get that fixed. The engine block was fine.

They put on a new head gasket and reinstalled everything. He kept the car for another day for tests.

After paying about $500 dollars for the repairs, the car was fine.

It looks like I blew a head gasket.

Some things to look for:

Hard starting in the morning (car has been cooled overnight)
A check engine light with the codes that lead to misfiring cylinders
Coolant in the cylinders, check after that car has cooled overnight.


It doesn't sound logical that a warped head and a blown head gasket will cause this weird overheating issue. But it looks like bad sealing between the head and engine will cause a havoc of problems.

I've speculated that the water pump wasn't pumping coolant at specification. But if you have your thermostat out and see water swirling in your radiator when the engine is running then the water pump is fine. Replacing that means a timing belt service. The timing belt drives the water pump in the d17 engines.

Well I hope that helps. Keep us posted!

Ckutch02EX

^^^I went through almost the same ****. My car was overheating at idle but not while driving. Replaced the fan relay and the car was good for 24 hours. Then it started overheating while driving. It's an 05 with 68k on it so I found it hard to believe it was the gasket at first but after it got worse I told the stealership to replace the gasket. They kept telling me it wasn't the gasket, they had the car for three weeks, replaced the fan motor and relay before finally settling on the gasket. Got it back Friday and runs like a dream. Spent almost 400 on tows, 183 on the relay, 300 on the fan motor and almost 2k on the gasket as well as no car for 3 weeks and pushing my move to NC back 2 weeks. Get the gasket looked at first and save your time and money. 7th gen civics seem to have **** gaskets.

GSmith215

Well, to a point, I get why it might be the gasket - but why am I not visibly burning anti-freeze or getting oil in my coolant (or vice versa)? The car, recently, has developed a rough idle when you start it cold (but not all the time, just some times). I just give it a little gas and the idle smooths out. It's not all the time, though.

Any thoughts on why I'm not seeing burning or fluid mixture?

pjb3

Head gaskets can fail in different ways. Look at the passages through a head gasket, there are cylinder, coolant, oil and oil return and think about the pressure in each. Using easy numbers the coolant is at 15 psi, pressurized oil is at 30 psi, return oil is at 0 psi and the cylinder varies from 0 to 150 psi on compression and much higher during combustion. If the gasket fails between a coolant passage and the outside of the head you lose coolant and nothing else. If the gasket fails between a coolant passage and a pressurized oil passage then oil goes into the coolant (30 psi to 15 psi). If the gasket fails between a coolant passage and an oil return opening then coolant goes into the oil (30 psi to 0 psi). If the gasket fails between a cylinder and a coolant passage you get a little coolant in the cylinder but mostly you get combustion gas in the coolant until you have displaced enough coolant that you overheat (150 psi to 15 psi). When you shut the engine off the pressure in the radiator bleeds off slowly but combustion and oil drop to 0 psi right away so some of the above reverse.
There is no one way that head gaskets fail so you have to look at each fluid and it may be a combination. It appears that the most common way for Civic head gaskets to fail is to allow combustion gas into the coolant.

JoshW

Hi all, new to the forum. I've already found a great deal great info on here with the search function.

I have almost the exact same problem as the OP with my 05 EX auto. (fine for a while, then getting hot idling, pushing coolant out the overflow) I first bled the system to remove any possible air bubbles and had to add about a quart of coolant. I also found that the condenser fan had a blown fuse, so that was replaced.

The car was fine for a week or two, then the problem re-started. I then replaced the thermostat, radiator cap, coolant temp sensor and fan switch. (Note that the fans still seem like they almost never come on without the A/C on, even if the temp gage is high, more on that later...)

The car was fine for two weeks and then the issue started again this morning when I dropped my wife off at work. Immediately after shutting off the engine, you could still hear bubbling in the coolant overflow tank.

I'm reaching the conclusion that it's the head gasket, especially after searching a lot on this forum, though it doesn't behave like blown head gaskets I've experienced / replaced on other vehicles.

One final thought on why the fans weren't coming on with A/C off. I noticed that while the gage was nearly in the red and the upper radiator hose was extremely hot, the lower hose wasn't nearly as hot (even after the new Tstat). I got to thinking that the fan switch is on the thermostat housing, while the temp sensor for the gage is directly on top of the head. In the case of a blown head gasket, I could see a steam / hot area forming in the head, causing the gage to skyrocket. The fan switch, however has not reached the fan turn-on temp (very high for these cars anyway), thus the fans stay on. I think I've confirmed this by pulling the connector for the switch and connecting both terminals, the fans then come on. Also with the old switch hooked up to the connector (off the engine), you can heat the switch (with a propane torch or likewise) to the point where it closes and the fans kick on.

As much as I hate to think of it (especially on a car with only 60k miles), I think a blown head gasket is the likely cause.

Comments, thoughts?

Josh

lazlong

Have it tested for exhaust gases or oil in the coolant before you go ripping it apart. Drive it as little as possible in the meantime.

JoshW

Exhaust test is a good idea.

Definitely no visible oil in coolant, or vise versa or any visible smoke out the exhaust.

I had a blown head gasket on my 94 Camaro, and it did not have any fluid mixing, either. The head gasket was blown between the cylinder and a coolant passage, resulting in over-pressurization of the cooling system and eventual overheating. The difference between that and my Civic is that once it blew, it was permanent, and the car would overheat every time it was run. This is so odly intermittent, and it's strange how it cools down once it's moving, (although it did it for the first time while moving today..). Water pump could be a suspect, I suppose, but if I replace the head gasket, I'll be doing a timing belt, water pump, and tensioner anyway, since the area will be opened up.

uk_surfy

I have pretty much the same issues with mine its an 01, am losing coolant on long or high speed journeys or if im sitting in traffic for long periods, had it looked at by lots of different mechanics including a dealer, all of them unsure what is causing it, they all wanted to replace everything from thermostat to radiator, so did nothing..

Seems to be gasses getting into the cooling system, as the oil seems fine and doesnt appear watery...

Came to the conclusion recently that its the Head Gasket as, after 12 months with the problem, theres some brown sludge building up on the inside of the radiator cap..

Going to bite the bullet and have it done now!

lexxie

Try this;
I've learned a few things in two years of this doing it.

-Keep your air on like your fans running (even just turned slightly)and stop at a light. Temps won't increase I guarantee. Always keep your fans running until you fix it. Also make sure your coolant is filled. Mine has seriously done this for two years. Laziness, I have come to believe that the condenser won't kick on, but was told it could be the fan motor and relay or a head gasket. But I don't really mind.

t00l117

Hello Everyone,

I am having the same issues with the coolant spewing out of the coolant reservoir bottle.
I have an 04 Civic EX with the 1.7L engine.
So far I have replaced the thermostat, radiator cap, fan relays, and temperature sensor with nothing solving the problem. I have had several mechanics look at it including 4 certified Honda techs. I purchased a head gasket kit and will be replacing it this weekend. I'll post back here when I get it installed.

BlueEM2

iTrader: (1)

^ Good luck, that generally fixes the problem

lexxie

bump you ever figure it out?

civiclover1991

i have an 02 Ex (auto with 170xxx) and ive been having the same problems with overheating, it overheats everytime i drive, and mostly overheats when i sit and idle, ive done several things to fix it but after a while it starts to overheat again, im not very good with mechanics,, i need a one on one with someone who can help!! i love my car but im at the end of my rope with it,, i dont have alot of money to work with so any help would be greatly appreciated,,,,, thanks guys

utahbmxer

Not to bump an old thread but I can confirm this is a head gasket issue. It's pretty common in this car. I was annoyed at this problem for months and months. Time finally came to replace the timing belt, which during this time the head was checked and machined. The problem has disappeared from the time this was done over 3 years ago. I could never completely bleed my cooling system. I thought I had all the air out and would let it idle for 10 more minutes, then as soon as I rev'd the engine, the water pump would force the combustion gases past the thermostat and I could smell and see them coming out of the radiator. Most cases you probably won't find coolant in the cylinders or anti-freeze in the oil, etc. They are failing in just the right area to allow the pressure from combustion to enter the cooling system at a low rate.

I was constantly draining the reservoir and putting the coolant back into the radiator, only to have it pushed back out a couple weeks later.

ExistEvolution

for 95 bucks buy a cometic head gasket. www.cometic.com

msedly

Having the same problem. Would this cause problems with the heat also? My heat works when I'm on the gas, but not when idling.

xRiCeBoYx

iTrader: (22)

it could. Your engine's coolant system is what provides the heat source for your heater. I'd do the "cheaper" stuff mentioned above first (thermostat, coolant system flush, fill, & bleed, replace radiator cap) to see if that solves your problem.

If it doesn't, you spent all of maybe $50, all of which would not have gone to waste. Unless, of course, it is a headgasket issue, then the coolant would have been "wasted" but still, you're not out much money

BlueEM2

iTrader: (1)

If enough coolant gets displaced in the coolant system with air from the head gasket leak. It certainally will create issues with your heating system. If your heating system is not working, that generally means your car is overheating or is going to start overheating soon and you need to stop driving it.

john222

I know the original poster has an 02, but for some of the others people posting there was a service bulletin issued for some 2004 & 2005 Civics where the factory coolant fill was wrong and resultied in scaling and corrosion in the radiator. The radiator then blocks up and coolant is pushed into the expansion tank and eventualy the heater blows cold and the engine overheats.

My problem is a head gasket. But some others may want to look into radiator blockage.

pb_boosted_es2

I had the same problem. Overheat when stationary and as I started moving it started dropping.

Did alot to try and diagnose and fix this problem. Everything failed from checking for bubbles. Adding new fluids. Changing thermostat. Problem fixer. Changed the headgasket.. seems to be a common problem.

pb_boosted_es2

Are you loosing coolant? specifically thru the overflow?