what are the "side effects" of a poorly fitting radiator cap?
 

This is not for me, its for someone else?

for example, you hear air from the reservoir container when you squeeze the upper radiator hose.

Well since the cooling system is pressurized to help raise the boiling point (about 45 degrees IIRC), then having a leak like that could lead to coolant eventually boiling, which would lead to overheating.

His question was about my car. It only overheated once or twice. Only after I'v been driving it all day in 100 degree weather with the AC full blast. but one day i came home wasn't payin attention to the thing. i get out of the car and hear boiling from under the hood. i pop the hood and the coolent in the overflow was full and boiling. That only happend once. but i think your right, i think its the Radiator cap too.

I read this.

http://auto.howstuffworks.com/cooling-system.htm

its informative.

But ^ HIS car doesnt over heat.

And his temp needle sits lower than normal!

AND there is no pressure in the cooling system at all, ever.

post any questions and comments, if you have any.

Yea dude the coolant wipl boil over into the resovoir happed to me get a new cap only like $10 from advanced autoparts

its weird.

Its not the cap.

IT seems to be the "mouth" of the plastic radiator.

We tried different Caps and you can still hear the "heezzing" noise from the reservoir when you squeeze the top rad. hose!
And of coarse no system pressure!

He might need a new radiator, or a way to make the 'MOUTH' seal right.

Wedon't know what to do.

we were thinking an extra o' ring or something.

yeah i went and bought a new cap today at AutoZone same thing happens. Also a bit off topic but i checked my codes again today and still reading 55. so thats good. i guess all those other codes were old before the tune up and stuff.

i'd be willing to bet that there isn't a thermostat on the engine either if in fact there isn't any pressure or overheating. being that this is a 93 with a 89 hood i wounder if the radiator is from some other car also.

good point!

Cr8zydrifter: CHECK to see if it has a thermostat. you can check by (w/ cold engine) squeezing the top (or bottom) rad hose and trying to listen for a little noise from the small bleeder thingy on a THermostat. It sounds like a little loose piece of metal inside. Trust me it makes a small soft noise.

Iono how to describe it.


also, check the heater hoses for pressure at operating temperature. To see if they are firm or flumpsy like the top rad. hose.

I think it could be that or......
Bad Thermostat reading to the ecu,or..........
A/C fan relay to your secondary electric fan is blown. You claim this happens when the A/C was on in 100* weather so I would check that first.

I think the main problem here is that the rad cap doesn't seal.

And maybe there is no/ or a bad Thermostat.

it only overheated once while driving and once right when i got home, thats it and that was a while ago. runs fine now, just there is no pressure in the cooling system. i just checked like you said and i can hear like a clicking sound, but only when you squeeze the bottom hose, and might i say damn its chilly out there and im ready for winter yet!

that means you DO have a thermostat.

That doesn't mean it is functional though. Check the heater hoses in the back for built pressure.

THey should be near the back top left (pass Side) small hoses maybe 1 -2 inches.

one on top of the other separated by about 4 inches.

just estimating it.

check the heater hoses while the car is hot or cold? because i just went to McDonalds.

check them when the car is hot/ normal operating temperature.

It makes sense to me that if the thermostat is working, this hoses should have pressure,

but maybe with a bad rad "mouth", and cap not sealing right, there might not be pressure back there.

PS I Don't have pics of the heater hoses in the back. Sorry.