Cooling System issues.

[kuruptR]

Car has been running great up until a few days ago. The car just started to overheat and looks like theres no flow. The engine is VERY hot, so hot that the valve cover will burn your fingers on touch. Looking at the radiator, the top half of the rad is same as the head, extremely hot. Top rad hose hot with lots of pressure. Bottom hose very cold with lots of pressure along with the bottom half off the rad being fairly cold, cool on touch. It looks to be at the thermo stat is not opening but why now? The aluminum neck (thermostat housing) is cold, so the thermostat will not open. The block is hot near it though.

Cooling system:
Koyo Aluminum Rad
Fal Dual Electric fan w/shroud
Fal Fan Switch
Greddy Rad Cap
Sard Thermostat *new at 3 months old.
Out side temprature is cool at about 12 degrees celcius

I have the Fal Fan switch's thermometer put into that rad at the bottom near the hose, where it is most cold. Thus cooling the radiator when the bottom of the rad gets hot, when the bottom half of rad gets hot the themostat should be open. I have tried putting the thermometer(probe) on the bottom and top, but the car still gets really hot.

I have bled the system of air through the bleeder screw. The heater was on full, and i did see bubbles and slight foam come out.

Should I run without a thermostat? or will this just mask the problem.
Could it be the drop in temprature out side?
Broken thermostat?

Give me a help out.

[s13silady]

i WOULD NOT run without the thermostat.. take out the thermo when the car is cooled off and throw it in some boiling water to see if it opens up. if it does then thermo is good. check waterpump after that.

GL

[SoSideways]

I think it's a faulty thermostat, or something's preventing it from opening.

Try taking it out and putting the thermostat in some water that's at the temp where the thermostat is supposed to open, and then putting it into the water and see if it opens. If it does, your thermostat is fine, but if it doesn't, then it's faulty.

You should also check the thermostat housing to make sure nothing's blocking the water or the thermostat from opening.

[chituntang]

How long has it been running good? If you have the car for quite some times (at least months), check for leaks and/or replace thermostat if it is bad. If your car has been running good for a few days, just bleed the system and test drive it to see what happen.

[kuruptR]

wouldnt the cold coolant at the bottom of the rad be causing it? or is the thermo causing the cold coolant haha? .... ill boil it when i get a chance.

[kuruptR]

I need help guys commmonnnn...

I just checked and replaced the thermostat. Same problem.
Now I checked the water pump, its good still. Should I start worrying now?

[SoSideways]

I need help guys commmonnnn...

I just checked and replaced the thermostat. Same problem.
Now I checked the water pump, its good still. Should I start worrying now?

Hmm... maybe somehow you're getting a bubble that keeps getting trapped right in front of the thermostat, thus preventing it from opening since it's not getting the hot water on it.

How are you running your cooling system?

I'm wondering if it's because somehow there's a pinhole leak somewhere and is introducing air/bubbles into the system, and eventually they all get trapped in front of the thermostat...

[blueshark123]

pressure test ur coolant system

[redclaw05]

thats why i run clutchfan and shroud :)

yea but check the thermo and let us know.