i've been having problems with my car heating up when it's not moving (sitting at lights or in traffic). i'm not sure if i have a coolant leak somewhere but i had to add a bunch've coolant into the radiator yesterday. when the car warms up an stuff some coolant goes into the resrvoir on the side of the engine bay. when the car cools back down, isn't the excess coolant supposed to drain back into the radiator hose an stuff? like my reservoir has always been above the full line but now it's all the way up to the brim. and when i open the radiator cap there's no coolant in the upper radiator hose.

is the coolant just supposed to get sucked back into the radiator hose when the engine cools and the coolant condenses? if it's not doing that is there a leak somewhere that's preventing a strong enough vacuum to build which would normally suck the excess coolant back into the upper radiator hose? i think that's how it works... idk maybe i'm way off. any info would be appreciated.

i suppose i could just keep putting the coolant back from the reservoir into the radiator but that'd be a pain...

-marc

='95 RS 5spd Red=
Matrix TypeX CAI
A'pexi Turbo N1
Nakayama GT5 17's
Ractive STB
GSX Calipers
AEM 12.5" X-Drilled/Slotted Rotors

255 is fricken short

i dont know what to tell you. the only thing i could think of is to check your radiator cap. mine was bad a little while ago and it caused all types of hell. $8 and easy replacement.

You may check the condition of the hose that goes from the overflow tank cap down into the tank. As it ages, the hose can fit loosely on the cap. If it feels loose or falls off when you remove the cap, then you have a problem. If it is loose and not sealing right, the coolant won't get sucked back into the engine. Its like trying to drink out of a straw that has a crack in it. You can replace the hose or put a small hose clamp on it (I put a clamp on mine).

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire

cool thanks for the advice.. i was kinda thinking it has to be something that's preventing it from sucking the coolant back when it cools... hawaii boy was sayin it might have to do with thethermostat too? would that prevent it from going back?

thanks!

-marc

='95 RS 5spd Red=
Matrix TypeX CAI
A'pexi Turbo N1
Nakayama GT5 17's
Ractive STB
GSX Calipers
AEM 12.5" X-Drilled/Slotted Rotors

255 is fricken short

Also, if you have lots of air in the cooling system, it won't be able to suck.

I have headgasket issues, so my situation is probably worse, but I bet money if you open your radiator cap (while the engine is COLD) you'll be able to put a bunch of water in there.

What I do: after filling the cooling system up, start the car, leave the radiator cap off, let it run until the thermostat starts opening. This gets a buncha bubbles out, and lets me throw a little more water in. Then when the cooling system starts kicking in and just starts to overflow, I cap it really quick. This effectively fills your cooling system to capacity, and starts the siphon into the overflow.

It never hurts to replace your thermostat, overflow tube, or radiator cap if theyre old. At most $40 in parts. If you overheat, its a lot more $$$ to fix a warped head.

did you ever solve this problem? I seem to be having exact same problem...

Me? Yeah I had a headgasket leak. I replaced the headgasket and the problem went away. When your engine is leaking compressed air into the cooling system, it forces the water out. The water only gets sucked back into the engine if there's a vacuum. If the cooling system's pressurized with air, it won't suck back in.