Sounds like you did not get all of the air out...

 

Yea thats what I think too, sounds like there is air in it. This is what I did, I drove mine for a bit, then slowly took off the rad cap, but dont do it if it is redlined, it will spray, all I did was un-twisted mine just a hair and the system went BURP, yes it actually made the sound, Then put it back on all the way. Then I had heat. I had do that a few times to get it going real good.

 

Well it turned out to be something simpler (and stupider) than that.

I was driving today and noticed the temp gauge swinging all the way to the right (and the check gauge lamp came on). Naturally I pulled over to see what was going on; as soon as I did, the gauge went right back to 210, I mean in seconds, so I got back on the road. I found by experiment that the gauge went up when I was facing downhill, and back to 210 when I was uphill. When I got home, I checked the coolant level in the reservoir: fine, although a bit darker in color than Dexcool is supposed to be. Then I squeezed the hoses. The top hose was hot; the bottom hose was ... empty?!

Let it cool down, and opened the cap. Nothing there. Damn radiator was empty, or at least the level was below where you could see it. I poured in some coolant (green, it was all I had around the house) and some water. Did this several times, and each time it went down and disappeared, until finally it stayed full, and I put the cap back on. Then I took it off again and looked at it more carefully. There's a metal bit on the bottom of the cap that's supposed to move when there's vacuum, so the coolant gets sucked back into the radiator from the reservoir, and it was rusted firmly in place... the coolant was overflowing into the jug, but never getting back into the engine. Once I got the radiator filled, the temp stayed at 190 where it usually is, and the gurgling went away. I hope I haven't broken anything by driving with insufficient coolant for $DEITY knows how long. (Although it can't be more than 2500 miles, since that's how long it's been since the last oil change, and he would have checked the level then.)

So I went to AutoZone tonight and bought a new cap. They sold me a 16 psi cap; said that's what was indicated. The thing is, the one that's on there now is a 15 psi cap, so I'm not sure if that's right. For what it's worth, Rockauto dot com shows several caps available for this vehicle. The Delco OEM one is 15 pounds, and all the aftermarket caps that they recommend are 16 pounds. So which one is correct? I can still return this one if it's wrong as long as I haven't destroyed the packaging.

(And does it make a difference if it's got the release lever or not?)