BDR cooling system under pressure?

[D111]

just wondering about something that seems odd to me I notice when my car is at running temperature I can squeeze the rubber hose that turns down on to the top of the motor thermostat housing with my fingers seems like there is no pressure in my cooling system when car is at running temperature?

Car runs at a consistent 180 to 190 the fan circulates on off everything seems fine but I just was under the impression that the system have to be under at least 12 pounds of pressure?

When I squeeze that rubber section I can hear the antifreeze slushing in the upper Stainless Steel Reserve Bank.

[Rwillia4]

Sounds like it is running well. 180-190 is below the boiling point of water. Which is below the point when steam is created and pressure is built up. Disconnect your fans and get the temp over 212 and see what happens.

[D111]

Originally Posted by Rwillia4

Sounds like it is running well. 180-190 is below the boiling point of water. Which is below the point when steam is created and pressure is built up. Disconnect your fans and get the temp over 212 and see what happens.

okay that makes sense to me if its not getting to the point where pressure would be created no wonder.

Thank you

[madmaxx]

My radiator cap on my lexus broke internally causing the cooling system to run at atmospheric pressure. Never saw any indication of overheating for a year. That being said even at 180 there should be some pressure. Is your cap good? If so don't worry about it.

[jhv48]

If you have a fuel injected engine, you probably have a 195 degree thermostat. So, at a running temp of 180-190 degrees, the thermostat isn't open and water isn't circulating through the radiator.

[D111]

I have 160 degree thermostat the cap is about 2 years old remember buying a new one to put a fancy aluminum cover on it wouldn't fit on the original cap,its a carbureted roush 342

[cbreez]

Under pressure doesn't mean that hose is always packed solid full of water, water runs through it but there can still be air. Think of the flow through a thermostat. Don't worry about changing thermostats and any "getting to boiling" experiments with you car, just drive it.
It's running at an great temp range, don't overthink it.

[Jaydee]

Any engine that warms up will create some pressure as the coolant expands, initially. If you release this pressure, then refit the cap, there will be no more pressure while the engine is warm, obviously if it start to overheat, it will then build up pressure to keep it from boiling.
If you don't get that initial pressure, it might be the cap leaking. This intial pressure can be high enough to lift the spring in the cap and flow to the overflow tank, then when it cools overnight, it sucks it back into the engine.
Hope this helps.
JD