i have my stock 5th gen civic cx engine in and i have an autometer water temp gauge hooked up.

before, i would normally run temps of around 165 degrees.
lately my car will get a lot warmer, reaching temps of as high as 240 degrees.

upon inspection, i notice that coolant is overflowing into the overflow tank but doesn't seem to be returning back to the radiator as it should.

i replaced the radiator cap and things "seemed" to return to normal for a little while. now it's running warm again and the coolant still isn't returning to the radiator.

i checked the hose between the radiator cap and overflow tank and there doesn't seem to be any leaks. i also checked the hose inside the overflow tank and there doesn't seem to be any leaks there either.

some help?... i doubt it's a bad thermostat because i don't think that would explain why coolant isn't returning to the radiator from the catch can. and for that matter, i doubt it's the water pump. is there some way of testing the radiator cap? perhaps i need new one again...

 

btw, the stock water temp gauge doesn't go to "hot" but it did rise to exactly halfway and slightly above halfway. i know that the engine normally runs about 2/5ths of the way up from cold to hot. (less than half)

any help???

 

Temp should be around 195-210, Does your car heat up when you're sitting in traffic, or when your're moving? Is your fan operational?

 

fan runs ok...

the car runs hot when i drive long on highway (coolant flows to radiator)
but when car cools down, fluid doesn't return to the radiator...

it's possible i have a pinhole leak in my radiator to overflow tank hoses...
i'm gonna check w/ a vacuum gauge this weekend...

until then, i just have to refill the radiator from the overflow tank manually before any long highway trips...

 

my engine runs at 240 too with a mugen thermo (opens sooner) its a crx b16 with a t3t4. any ideas or suggestions. thanks -Alex

its prob. just the way i have the radiator set. darn hasport mounts


Modified by toyosupr at 2:38 AM 6/14/2004