I did take the radiator cap off and it bubbles up releasing pressure? Bad cap, but it’s new and the radiator was recently re-done????
How old is the thermostat? Did you install it? If you didn't, replace it. I drill about an 1/8" hole in the perimeter just to help get air out of the system. After checking to be certain that the lower hose had an inner spring, leave the cap off and fill the system with the engine running. Run it long enough for the thermostat to open. Fill the system slowly so as not to have it come back out of the top of the radiator when the thermostat opens. When the coolant level is constantly about 1" below the top, put the cap on. let it run a bit, shut it down, check for leaks.
I did not. Purchased the car from the second owner last Spring and the drivetrain had been rebuilt approximately 6K miles ago...………. I hear you on the drill as I like to do that with mine as well. What temp does everyone use, stock 195 or less????
Fired it up this afternoon to warm her up. After idling for maybe 5 min, the upper hose was really HOT so I shut her down. Tons of pressure in the system as I eased the cap off after a few minutes...........
A thought here..... is the thermostat installed the correct way? Have you warmed it up with the rad cap off to see what happens?
I ended up pulling it last night, and yes it was installed properly. I bought a 180 degree unit that has the weep hole already in it. Probably get it back together and have the same issue! I am going to pull the upper and lower hoses along with the bypass. Upper is in very good condition, lower and bypass ok and may replace......
Suggestion - A test - remove thermostat, reinstall water pump, fill with coolant and run the car. That way will tell u if thermostat is defective. be sure u 3/4 fill the overflow container.
I already replaced it and flushed the system. Ordered a new radiator cap from C.A.R.S today as well.......
