Richard, please pardon me for interupting but unless I read your posts incorrectly you have a mix of green antifreeze, dexcool and stop leak in the system right now? If so I would suggest you back up a few steps and drop the antifreeze and discard it. To the best of my knowledge dex cool and green antifreeze are not compatible. In addition, stop leak can plug the tubes in the radiator. So I'd get that stuff out of there as soon as possible. As to the leak, the 89 3800 has a separate tube for coolant that goes from the intake to the throttle body. Chances are good it has rusted from the inside out and needs to be replaced. This thing is one big PIA to replace and the last replacement we got was not a bolt in fit, the base plate on the engine side had to be ground down a little to fit flush against the intake manifold.