Albino Dragon

On my girl's civic after she drives around for a while, 15+ mins of city driving, and we get out of the car the coolant in the reservoir is boiling. The cars temp gauge appears to be working and is never showing that the car is hot.

Any ideas? Radiator, radiator cap, air in the coolant system, not enough antifreeze per unit of water?

Jayson S.

What is year, make, model, engine type, mileage and etc.???

If after 15 minutes the coolant is boiling than there are a few things wrong.
1. Get a new temperature sender. If coolant is boiling that means temp is actually at 212+ degrees fahrenhiet, so your the temp sender is gone.

Is the fan coming on?? If no fan than change Engine Coolant Temperature (ECT)Switch Sender or you can test yours by following testing procedures in Helms manual.

2. I would assume 1 of 3 things is going on. Either water pump is shot, there is a head gasket problem, or coolant needs bled badly.

Here are a series of tests and things to check to narrow the possibilities:

Look around the engine bay for traces of coolant leakage. When coolant leaks and dries up it leaves a white trail on the engine.

Check hoses for leaks. Could be letting air in lines.

Inspect area near water pump. Look for white traces or areas that look wet. Checking for Water Pump failure.

Do a compression check. Low compression check may indicate compression blown off into coolant jackets.

Flush coolant system. Check for oil in coolant. Tells you if head gasket is gone.

Remove thermostat and then run car and see how long it takes to heat up.
If car heats up very quickly and overheats then water pump or head gasket is for sure screwed.

Hope this all helps. Please answer my questions so I can better help you out bro.

Jayson S.

Albino Dragon

94 Civic CX w/ 70k miles

Here are some other details: she bought the car three months ago and we knew at the time that the head gasket was gone. So I replaced the headgasket, water pump, thermostat, and timing belt. I had a friend check the head to see if it was warped and it was not. All parts were replaced with OEM parts.

There is no oil in the coolant and I ran the car and removed the rad. cap to see if there was any pressure built up in the coolant system and there was not, which indicates to me that the head gasket is still good.

I am not at home right now so I cannot look over the engine for anything that looks unusual but will as soon as I get home. Could the rad. cap cause this? I noticed that it is not the OEM radiator cap and it kinda worries me...

Confused dragon who hopes the head gasket is not gone again

Spade

Sounds like two possiblities......
1. Not enough antifreeze in the water.......(extends the boiling point)
2. Not enough Pressure in the radiator cap. It should be something close to 1 atmosphere or .95 atmosphere. If it doesn't say that and it says it is 13-15 PSI, it is an american replacement.

The higher pressure the radiator cap the higher the boiling point of the coolant.
Careful you don't go too high for the radiator might not be able to contain taht much pressure.

Remember, antifreeze helps raise the boiling point just as much as it helps lower the freezing point.
50/50 mixture is the best for boiling and freezing points.
Also, antifreeze contains anticorrosion goodies.

samdawgsol

You may mineral deposits clogging up your radiator if you dont use distilled water to fill it, go buy a bottle of radiator cleaner and do its procedures like it says on bottle then fill it up. And make sure you had the right mixture of water and antifreeze, not enough antifreeze will make it boil sooner. Your thermostat (radiator cap on my honda) could be the problem. Make sure you have the right one on.

AssPenny

You say its boiling in the resevoir... are u sure its not just air being blown out of the radator into the resevior making it look like its boiling? like blowing air through a straw in a glass of water?


[Modified by AssPenny, 5:37 PM 4/18/2002]

Albino Dragon

I will have to check this for sure when I get home, it looks like it is boiling.

Thanks everybody for the suggestions! Rad. cleaner and more antifreeze going in tonight, possibly new rad. cap tomorrow!

fixhondas

did you replace the headbolts when you did the headgasket? The headgaskets usually failed from headbolt stretch.


[Modified by fixhondas, 6:07 PM 4/18/2002]

Albino Dragon

No I did not replace the head bolts I have never heard that suggested before....

fixhondas

This is most likely your problem. Honda has an updated metal headgasket and headbolts that are required. 88-95 non vtec civics all have this problem. You can remove the valve cover and try to tighten the head bolts to see if any are loose- you will probably find that the two in the middle are loose. With the radiator full remove the radiator cap and start the engine. Does coolant spray all over?

Albino Dragon

I have ran the car with the radiator cap off and there was no coolant shooting out of the radiator.

fixhondas

Well, if it is not gushing, it could be slowly bubbling. Was it fine for a while after HG replacement?

fixhondas

I use a "Spill free funnel" to fill up and run the car to check for bubbles.

Albino Dragon

I worked on it last weekend, trying to bleed the air out, and there was no bubbles or anything coming out of the radiator. I am not sure it is was fine for a while because it is my girls car and she seems to be oblivious to anything her car does. I rode with her last weekend and when we got out of the car I heard the hissing noise from steam coming out of the coolant reservoir.

fixhondas

When the headgasket leaks slowly- it forces coolant and steam over into the reservoir. It usually wont pull it back in when it cools.

owen_the_soyboy

find a friend with a honda similar to yours, use that radiator cap for a try

deepnite

50% / 50% water and coolant ?

Albino Dragon

[B]Update:[B/] I went home last night and added antifreeze and put on a diffrent radiator cap. I also took off the valve cover and checked the head bolts, all were still torqued to spec. I inspected the engine bay for traces of leaking antifreeze and could not see any and I couldnt find any leaks in the hoses. I let the car warm up and the fan did come on and then I went for a drive and didn't lose any coolant and it did not start to boil... I told my girl to keep a close eye on it so I know what is going on but hopefully added antifreeze and diffrent radiator cap helped.

Everybody that helped out thank you very much


[Modified by Albino Dragon, 6:37 AM 4/19/2002]

fixhondas

Something else to look for- if you remove your vavle cover when the engine is cold- you will usually see a milky muddy gel on the bottom - this is coolant and oil that is mixed. Good luck