I realize this problem has been beat into the ground but its the first experience I've had with a Honda Civic. I'm pretty mechanically inclined and have generally repaired all my own vehicle short of major overhauls. I approached this problem like I have in many other vehicles.

Here's the problems..

Its a girl friend of mine. She just out of the blue kept saying I'm having problems with my car.. Have been for a long time.. Its been in and out of the shop, etc.. etc.. As I've drilled her down she's told me some key things.

1.) The temperature gauge fluctuates. Sometimes reaching the overheated stage. Bad I know and there could be major damage as a result. Now, I immediately started saying.. Thermostat.. Leak.. She said, I've had it in the shop 3 times in the last year. They replaced the thermostat.. Brand new radiator.. And the last time they said they had no idea what was wrong. She said, "I'm just going to drive it till it dies."

2.) Yesterday she tells me that it stopped blowing hot air. I asked if they ever looked at the heater coil or blew the system out and she said they did all that. So, last night I checked and it appeared to have coolant.

3.) Today still no hot air. I met her at lunch with coolant and was going to top it off absolutely determined it was low. Well, it didn't take much. Then I drove it and checked again and still was full. But an odd thing happened. While I'm looking for leaks, which I didn't see any, suddenly it gurgled and I poured 1/2 gallon of antifreeze in it.

4.) After work she is saying that its been better than it has in a long time. Hot air again, temperature staying at mid point.. So, definitely was low on coolant.. But why.. I mentioned thermostat again, of course she swears it was just replaced. I couldn't see any leaks and assumed the coolant was evaporating with the overheating.

Am I missing something here. Could it still be the thermostat? Even though it was just replace.. I feel like its an easy problem.. Clogged system.. Thermostat.. Water pump.. Maybe she was just ripped off. I will have time this weekend to dive into it pretty good and was looking for suggestions. Any help would be greatly appreciated.

Thanks!

 

I would guess previous person installed the radiator didn't properly air out the system.

 

My car (which I unfortunately just bought ) is exhibiting much the same symptoms.

The only differences are my temperature doesn't fluctuate often, only slightly above the halfway point.

The heat in mine works awesome when it's driving. At idle and lower speeds, it works sometimes, sometimes it doesn't.

I've noticed there were some coolant leaks on the bottom of the car. I also noticed one of the times when the car temperature went up slightly and I pulled over there was coolant sprayed on the interior of the hood. But the car runs great.

I had it pressure tested - no leaks. Compression test - cylinders good. Took it to various mechanics who said it was fine. Today I took it to another mechanic and here is the diagnosis you want to hear...

It's a blown head gasket. The bad gasket is forcing water/coolant back into the reservoir and it is overflowing and spraying, causing coolant loss. This is also causing overheating. It's affecting the heating system too.

Found these threads on it...

https://www.hondacivicforum.com/foru...ng-cold-87444/

http://www.civicforums.com/forums/36...overflows.html

Almost the same exact symptoms as us.

I would not mind replacing the gasket as long as that solved the problems. I am NOT convinced of this however.

Maybe someone who has had this fix done can chime in and tell us if this did indeed solve all the car's problems. Other than what I mentioned (which is significant) my car runs fine.

 

I plan on taking a longer look at it this weekend. Hadn't had a chance to have it in my garage with all my resources and tools. I'm going to give the coolant system a pretty good once over, in doing so bleeding the system of air will be one accomplishment. I hope for her sake thats all it is. Like I said, and the poster above mentions, I'm sure worse damage is a result of the initial problem. Although I honestly see zero signs of any spraying or leaking of antifreeze. She's looking for a new car but it will be a few weeks at the least. She has two kids and I am just trying to get it to atleast limp along till then. Which I think I should be able to do. I keep telling her, the cooling system isn't really all that complicated. There aren't a lot of options to fault. Logically they should be able to be eliminated or isolated. She is very pessimistic about it with the experience she's had from her mechanic. Blows me away she's spent money 3 different times and still has a car that isn't right. With them finally concluding there is nothing they can do..

 

Get the system completely full. Start the engine cold with the radiator cap off and rev it. A leaking head gasket will usually have bubbles of air streaming constantly out of the radiator. A severe case will blow coolant out. A more specific test can be done at a garage by forcing compressed air into the cylinders with the engine stopped and watching for it to appear at the radiator. This is a "leakdown" test.

The first symptom of a bubble of air in the engine is that the heat doesn't work, or only works at driving rpm but not idle. If such air pockets continue to form even before there is overheating, it's the head gasket.