Hey guys I'm having an overheating issue with my civic. It'll drive fine when your driving around town or on the freeway (short distances) but will have to refill with coolant but when you take it for a drive going up hill it'll overheat in an instant. Don't know whats wrong with the car. Assuming theres alot of air stuck in the coolant system because it has alot of air bubbles but then I've been trying to bleed it for like an hour and it still has air bubbles. Don't know if it's the water pump or the radiator? Thanks!

 

Sounds like a blown head gasket.

 

Thanks for the input but I checked it with the coolant thingy (you put some coolant into the tester and if it change color then it has a possiblility of a blown head gasket) and it didn't change color so I don't think its a blown head gasket. But how do we really know if we have a blown head gasket or not without taking off the head and stuff? Thanks!

 

radiator prpb. has some air pockets in it or the heat sensor is shot.

 

could be also you have a leak somewhere in your coolant lines, i suggest check the small thigns then move on to the bigger main things, you can tell if u have a bad head gasket by your oil becoming coffee color brown

 

Also check to make sure the fan is kicking on regularly.

Had similar symptoms when my fan had a short in, so sometimes it would turn off when driving up hills or after hitting a bump. Took a while to figure out, cause when the car was parked on level ground it was always running when I checked it the first few times.

 

Thanks for the input guys. did a pressure test and it doesn't have any leaks. i'm thinking its probably the head gasket but i hope its not cuz its going to be a pain in the a** to fix. any one know any good write up on how to change a head gasket?

 

Will signs of a blown head gasket always be white smoke, and coolant mixing with oil?

 

Nope.

 

If it's the same tester I have you don't put coolant into it, in fact you DONT want coolant in there. The one I have you squeeze a rubber bulb to draw AIR from the radiator into the special test fluid and if it turns from blue to yellow you have exhaust gasses in your radiator indicating a bad head gasket or crack in the head/block. You have to lower the radiator coolant level an inch to use it (or I suppose rig up some type of adapter).

Do you have a different kind of tester because pouring coolant in sounds easier...

White smoke will not always come from the tailpipe with a blown headgasket. I've had headgaskets where coolant only leaked into the crankcase (white crud under the oil cap), where it came out the tailpipe as white smoke, where exhaust gasses only leaked into the cooling system (causing the coolant to be forced out the overflow and ultimately overheating). Depends where the gasket fails....

Also, a clogged radiator (or other cause of poor circulation like a bad pump, air cavitation, bad/kinked hose) will cause overheating at speed (as in climbing a hill). The partial clog will cause a loss of cooling capacity that will only only show up under certain circumstances, like extended high speed driving, uphill etc. I had a truck that would slowly heat up when driving on the freeway but was otherwise fine on the street, idling etc. Had the radiator rodded out and it was fine after. Honda replacement radiators can be had cheap.

 

Blown head gasket will also send compression bubbles back through the radiator and/or reservoir. A stopped up radiator would be more likely to heat up while sitting than driving.

 

i had a very similar problem a few years back and the very first thing i did to try and fix that problem was "flushed" my radiator and it worked i haven't had any issues since, just something to try if u havent already

 

A clogged up radiator will heat up at speed. A bad fan will cause overheating at a standstill.

 

First of all, I want to thank everyone for there great inputs! Now my plan is to do the cheapest first which is to reflushed the whole cooling system and if that doesnt work then I'm going to switch my rad, water pump, thermostat since I haven't switched any since I've got the car (5 yrs). If that don't work then guess it's time to tear up the engine and fix the head gasket.

I'll give you guys an update of how it goes.