Sounds like an air bubble in the system. Run the engine with the radiator cap off. Let it idle and bring it up to running temp, where the thermostat opens and you say see the coolant flowing when you look in the cap hole. Turn the heater on full blast. grab the throttle on the TB and gently rev the motor up and down and keep an eye on the flowing coolant. You should see alot of bubbles popping through the radiators core tubes. Keep doing that until you see the bubbles stop for the most part. If they dont stop, air is getting in the system from somewhere, and you need to look around. Do you have any leaking hoses? Is the heater valve leaking? Are the radiator hoses in good shape...like they're not collapsing? Everyone was telling me it sounded like I had a blown head gasket, but after I pulled my intake and replaced that crappy steel shimstock intake gasket with a fel pro 1 piece pan type intake gasket, and threw in the 100 dollar autozone F-Body radiator, my overheating woes ended for good. The only time the temps have climbed back up, is when Ive had leaks in the system. Usually, if coolant is getting out, air is getting in.
I installed the F-body set up, with a new H20 pump, and I tested the T-stat.
The hoses are new and are not collapsing..from what I have seen.
The heater core is bypasses.
I use the fel-pro 1 piece intake gasket.
When I fill the Radiator I have the cap off, wait till the coolant drops down, re fill and then put the cap back on the rad. When i do this I use a small wedge to keep the RPM's to about 1500-2000.
There is no milky oil, nothing on the cap or breathers, and the oil level is good.
From the coolant that is in the Rad/over flow that does not get sucked out, there is no oil.
I dont notice any seepage along the heads, or an new leaks on the floor.
I also made sure the drain plug is tight.
When I drive the car, there is no smoke gray, black or white. The car actually runs great.
The only other thing I can think of, is if there is coolant seeping into the in combustion chamber, which on a cold start causes a very rough idle and moisture out of the rear pipes. But after 30 sec everything clears up.
AHHHHHHHHHHHH...is all I have left....LOL
Thanks for all the input, anything else?