Cool engine temp

at the bottom of the radiator cap the little metal disk is hanging down and the reservoir had extra coolant in it.
Looks to me like the system is open as there was no pressure, i drove it 30 plus miles then opened the hood and that is what i found

the cap would have to be junk. Its open with no pressure on it.

Its been fun

Good Night

PLEASE PLEASE PLEASE go and spend the 20 bucks and get an Infra Red thermometer and aim it at all the important stuff under your hood and give us the readings…IT will tell us 90% of the story.

Also the cap issue is only a problem on the EQUATOR…you Sir are FAR from it Of course you need a new cap… I’d love to hear the readings of the IR thermometer…it will help you and us figure out whats what

Blackbird

Once the cap stopped holding pressure on my 1988 Accord.
The symptom was the reservoir would overflow when I shut the engine off, but only after driving on the highway.
The pressure is needed to keep hot spots from causing a boil.
I recommend changing the cap and thermostat at least every other coolant change.

"I recommend changing the cap and thermostat every other coolant change. "

Caps & thermostats are so cheap I just change them every time. Heck - I recently changed my radiator cap just because I didn’t like the way it looked at me.

The small metal disk is the check valve that allows coolant to be drawn back to the radiator when the engine cools and the coolant contracts. When there is pressure in the radiator the disk is held in its seat… And no one waits here for your posts.

I know no one waits for my posts but when i see mine at the top then getting buried without reply i wonder.

"The small metal disk is the check valve that allows coolant to be drawn back to the radiator when the engine cools"
The engine was hot with an open rad cap

I am not sure that you understood the function of that disk. With the cap off and the disk facing upwards it should be resting in its seat. It should be held in place with very slight tension from a spring. If it is dangling loosely the cap needs replacing. But if you throw the cap away and drive capless the engine will not run at a cooler temperature.

You have just confirmed. Yes…The cap is junk!

Thanks