Radiator Fluid Overflowing

[b16_704]

This is on my 97' civic ex. a few weeks ago i noticed fluid overflowing out the reservoir. i filled the radiator up but after driving for a little bit it would overflow out the reservoir again. so far i replaced the cap and thermostat, a couple days later the heater hose busted on me and the car overheated a little bit. got that replaced, refill the radiator, let all the air bubbles out while the car is running w/o the cap on. but today when i drove to work, i popped the hood just to check to see if everything is ok but it wasn't. fluid all over the airbox and fluid overflowing out the reservoir again. i don't hear or see any sign of a blown head gasket. maybe the thermostat i bought is faulty? what do you guys think?

[LandoAWD]

i don't hear or see any sign of a blown head gasket.

That's why they rent compression testers.

maybe the thermostat i bought is faulty?

Pull it, heat up some water on the stove, and test when it opens.

[biggie]

Seems the car is overheating. Water pump good?

[b16_704]

Seems the car is overheating. Water pump good?

possibly but car isn't overheating ever since i replaced the heater hose.

[Crusher103]

Its your headgasket, its gone. My car did the same when it threw its HG.

[eidas007]

Pressure test the cooling system. Compression test all the cylinders.

Do you show any signs of mixing coolant and oil.

[Crusher103]

Its most likely a leaking HG, a little oil will enter the system but the car is eating coolant at the rate you will never notice it.

I had this same exact problem. The car lost power a little power, it had an overflowing reservoir, and it got progressively worse till i couldn't drive the thing for more than 2.5hrs with out it overheating.

[eidas007]

Yeah, but it's always better to confirm before you go tearing stuff apart.

[b16_704]

Pressure test the cooling system. Compression test all the cylinders.

Do you show any signs of mixing coolant and oil.

haven't tried testing the cooling system or do a compression test yet. what i did do was checked to see if the new thermostat was working properly by dropping it into boiling water, it did open but only about a little less than 1/4". is that normal? as for coolant and oil mixing, i don't see none on the dip stick or when i open the radiator cap but i do see these slimy greyish/brownish stuff around the reservoir walls. now that i think about it, that could possibly be oil....

[b16_704]

went for a test drive after putting the thermostat back on and only filling it up to about where it barely pass the fins on the inside and it's still overflowing. i have a feeling it is the head gasket is going bad..

[Ws9TransAm]

Test first assume later. Since you can shove a turbo kit on a 315k mile car you can afford to pay someone a hours diagnostic to see whats wrong.

[b16_704]

was talking to some of my buddies and they said it sounded like the radiator (250k miles on it) is clogged and not a bhg. the lower hose is cold most of the times and barely gets warm. i'm gonna try to either flush it out or buy a new radiator to see if it's the problem.

[Crusher103]

Clogged radiator? Im willing to bet money that is not the problem.

[nismo7sx]

it could be something as simple as a bad rad cap,. pressure test the cooling system first. then go from there.

[LandoAWD]

I think the point is being missed and replaced with supposition; TEST.

[b16_704]

OK fellas just got done pressure testing the cooling system and compression testing. couldn't get the cooling system pressure tester to seal tight but did get it to about 5 psi and already i saw what was causing it to or which i thought was overflowing out the cap was actually a crack radiator right between the top plastic end and the aluminum fins. so glad it's not a BHG. and here's the compression test results in the firing order:

1. 190
2. 185
3. 182
4. 190

will update again once i get a new radiator installed and we'll see what happens from there.

[Ws9TransAm]

OK fellas just got done pressure testing the cooling system and compression testing. couldn't get the cooling system pressure tester to seal tight but did get it to about 5 psi and already i saw what was causing it to or which i thought was overflowing out the cap was actually a crack radiator right between the top plastic end and the aluminum fins. so glad it's not a BHG. and here's the compression test results in the firing order:

1. 190
2. 185
3. 182
4. 190

will update again once i get a new radiator installed and we'll see what happens from there.

See, not a head gasket..... Every cooling problems not always a head gasket....

[b16_704]

just got the new radiator and both upper/lower hoses replaced, so far so good. i'll know for sure once i test drive it for longer distances tomorrow. thanks everyone for their help!

[eidas007]

Glad you got that sorted out.

[b16_704]

ok so it's been a few days now and everything is still good but there's one little thing that has been bothering me. normally when there's a lot of pressure in the cooling system, it will force some fluid to the reservoir, and once the engine has cooled down it creates vacuum and pulls the fluid back into the radiator correct? if that's how it works then i don't know why my car isn't creating any vacuum, the fluids just stays in the reservoir. when i open the cap the radiator is a little low.