Civic EG

Appearantly this is very common on these cars. I have done and still am doing some research about this . I just figured i would post this up if someone could help. Well at first my car just had idle surge. Then my heater would only blow cold air until the temperature reading on my gauge went all the way up to hot then it would blow hot air and the temperature would drop. (I thought this was a sticking thermostat) Then the temperature would go all the way up to the H on the gauge and drop no matter what the heater blew(hot or cold). The after a 40 mile ride i shut the car off for about 5 minutes then when i started it the motor was idling poorly and wanted to stall, thats when i seen a lot of white smoke pouring out the exhaust. I reved it a couple of times and there was a lot of white smoke that came out the exhaust( i thought it was a head gasket) but the smoke cleared up and it idled fine. I checked for any leaks and there were none. I replaced the thermostat and filled up the coolant system. I took the car for a 10 minute ride down the highway and the gauge read normal. When i got home i let the car idle for a couple minutes while i went in my house for literally a minute. When i came out there was coolant all over the engine and the car was idling poorly again with white smoke pouring out the exhaust. I reved it and the smoke cleared but the motor just kept idle surging. The coolant wasnt dirty and it has a new thermostat. It also seemed like the lower radiator hose was cold which means that the thermostat never opened? Also the upper radiator hose seemed like it was swollen to the point where it looked like it was gonna burst. I also read that the little plastic L piece on top of the coolant expansion tank cap has a spring in it, is that true? Mine broke along time ago and i have vaccum t fitting in its place with the other end capped off. Any info would really help. Thanks and sorry for the long long post.

now this has not happened to me "knocks on wood" but if i think right here is why some things happened as they did.....

Did you happen to check your thermostat rating? sometimes they put a high rating on them and that is why they dont open most of the time and thats why i always try and find the lowest possible.....anyhow that could be one reason why it did not open another well lets just say thermostats arent the most reliable things in a car they can go bad very easily or last for a long time its hit or miss and quality counts as well.....

but the reason your upper hose looked like it was about to burst was probaly the heated coolant and gasses expanding or you may have installed your thermostat the wrong way really it sounds to me that if your thermostat was replaced id double check to make sure it was done correctly and then see what happens

and you really should not block anything off if i am reading right you blocked off the hose that connects to the overflow res? thats the only one i can think of that comes off the radiator.

sounds like warped head or blown head gasket to me

well i put the thermostat in the way i took the old one out and i believe it only fit in one way and it was 170 degree thermostat.
Here are some pics of the tube. The tube that goes to the radiator is not blocked off.

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Is there anyway to tell if its a wapred head or head gasket without taking off the head? The car does have 39,300 original miles.

Also, i forgot to mention that i replaced the spark plugs and wires because i havent replaced them yet. On one of the spark plugs i took out the threads had a lot of oil on them. It was just that one plug. Would this further the head gasket guess?

the overheating is what caused the head gasket to blow or head to warp. I'm betting the head warped which caused your HG to leak. Then pressure from your cylinders made its way into your coolant system putting all the pressure on your hoses and causing the coolant to leak out. When you see the temp needle get up to H, shut the engine off immediately or this could happen. I would say your HG will definitely need replaced and you will need to have the head checked for warpage.

Once the damage is fixed, you will need to find the root of the problem. your idle surge that you first experienced is often caused by air pockets in the coolant system from not having enough coolant. 40 miles of driving with not enough coolant can definitely overhead & warp the head. The white smoke was coolant entering your combustion chamber. It happened at first when the engine was cold then when the engine heated up it expanded and reduced the tolerances for the coolant to leak through. As the situation got worse and the engine overheated more you burnt off more coolant so there was even less than you had to begin with. Also there was more pressure escaping from your combustion chamber into your coolant passages, forcing more coolant out of the system. It is the snowball effect. At the first sign of a problem, stop driving or things will get bad and do more damage to other parts. That's a good automotive rule in general.

Yes i need to take the head off and check it. ( I guess i should look into a mini-me swap) Thanks teal!

Yeah I've got the same problem with my D16Z6 (except the idle problem). Currently in the process of swapping over the HG.

There is a way of getting it tested to see if it is the HG without having to take the head off (even though the symptoms are obvious). Take it to the local garage and have it sniff tested. At first I thought it was a problem in my cooling system. My top hose also blew up whilst I was driving a good 80miles. It turned out to be a build up of exhaust inside my cooling system that caused the hose to blow. Problem: HG leak. Should have the head off tomorrow night, going to get it checked and skimmed anyway just for future proof.

Thanks Sizzle. There is def a build up of extra pressure in the cooling system.

You also might want to check your water pump. My car had a similar problem minus the swollen radiator hoses. would fill the rad and res, and then drive and car would heat up turn off my car check the reservoir and it would be bone dry. I took it to a mechanic finally and he said my water pump was fucked and water was just leaking out from there and evaporating from the heat since the pump was not pumping anything. Just something to think about.