Radiator coolant is only circulating when radiator cap is off

Thermostat

If it's acting like a carburetor to allow circulation with it off check the overflow hose coming off fill reservoir and make sure it's not kinked or clogged up somehow. It's just a black hose coming of the reservoir that leads to nowhere.

Why would the radiator cap prevent thermostat from opening?

Oh that is supposed to be opened up ? I kinked it on purpose because I didn't know what that was for. Thanks

The electric fan doesn't even start until 235* it isn't overheating.

Disregarded as irrelevant data. You have no idea what its doing if the cap is on, unless you have a clear radiator. Do you have a clear radiator?

Does the temp gauge go into the red? Is it pushing coolant out onto the ground? Can you hear boiling in the engine? If no then it's not overheating.

Last Edited by BRIEF on 05/19/2017 01:01 PM

Because the thermostat is in the cap. Call Pep Boys or O'Reillys and they will tell you the same thing

Oh so 235 is fine ? It just runs hot like that because it's staying idle and not getting air circulation from driving ?

Yes those are the simplest to change...

Where on the gauge is the needle? midway or close to hot in the red?

If the electric fan cycles on and OFF then you are not overheating, it is regulating the temp.

Well my friiend has same car and hers sits around 185 while it's idle. No it doesn't go in the red but every time I open that bleed valve near the engine I hear a hissing noise of air coming out so it sounds like there is air in the lines.

I just changed my coolant yesterday

So scared watching the temp gauge rise cuz I don't have have a pressure full kit just used a funnel to bleed air

Topped off this morning but runs great now

It took a while for thermostat to open while upper hose got hot as hell

In that case, they would be as ignorant as you are.

Last Edited by last one on 05/19/2017 01:07 PM

Yes the fan turns on and off. But should it get that hot to where I need the fan when it's just sitting idle? Takes about 15 minutes for it to get to where the fan turns on

If it has an air pocket then you have a leak, but so far you have not given me any info that indicates that it's overheating.

Last Edited by BRIEF on 05/19/2017 01:06 PM

That's perfectly normal. The fan is for when you aren't going 70 down the highway pushing air through the radiator.

:hestonlaugh2:

He's right, if you remove the cap, the thermostat in directly under it and can be changed with no tools.

must be a domestic thing

Yeah every time I run the car for a couple minutes and open that bleeder valve I hear air hiss out for a few seconds before the coolant comes out. I don't think it's a head gasket problem because when the radiator cap is off I don't see water bubbling out. So that means the leak is probably one of the radiator hoses huh?

In the middle of all of this good advice, you also need to make sure that you have a 50-50 mix of coolant and water in there. This ensures summer cooling as well as freeze protection in the winter. If it's not 50-50, it will run a little hotter.

WTF? Learn something here on a regular basis. Thanks.

Any part of the cooling system can leak, why assume it's a hose?

Do you have to add coolant? How much do you add and how often?

that's inciredly convenient

I'm with him. You need to buy a clear radiator.

Thermostats work on pressure as well as temp.

DOES YOUR COOLANT LOOK LIKE MUD??