Pressure in cooling system..

Hi guys! So once a month or so I like to check the fluids in my truck and the wife’s 4runner. I was checking the fluids today in my truck and when I checked the coolant in the radiator it had pressure in it and spewed some coolant when I took the cap off. The truck 16sr5 5.7. was cold and had been sitting for about 24 hours. Drove it around town yesterday to run some errands and that was it.

Is this normal for these engines? Any car I’ve ever been around looses coolant pressure when it’s cold. I’ve never seen any smoke out the tail pipe other than condensation “smoke” no milky oil, no milky residue in oil cap. No overheating. My truck only has 76k on it so I can’t possibly see it has a head gasket out but trying to see if this is a normal thing before I go digging around.

 

Anyone?! I’m leaning towards a bad cap

 

I don’t know, but while cold you can start engine with rad cap off and see if there’s bubbles or pressure coming up.

 

Did that one. Ran it for a good few minutes not one bubble showed itself during that little test. I’m kinda ruling out a head gasket at this point.