Perfect. The coolant passage is the double teardrop shapes laying down on the bottom edge, below the bore. That'* the surface that mates to your SC. The coolant comes up through one of the yellow o-rings in the first pic posted, through the SC, into the TB, back out, down through the SC, and out the other coolant passage o-ring in the lower intake.

Thanks, Doc. Perfect.

thats what I'm here for

Thanks for all the replies. I did not mean to mislead people but this problem is occuring in my 99 Grand Prix GTP. The Bonneville only has 192000 on it now is running fine. Back to the Problem. I have not drained the oil and examined it myself. I don't think the dealer did any more than check the dipstick. I will do that this weekend as the car is not being used until I find the problem. If it is going into the oil I assume that cannot be good! I'll also check the other possibilities that were brought up. Thanks again.

If you are losing coolant into your intake YOU WILL notice alot of white smoke out the exhaust. With the amount of coolant you are loosing your exhaust will be billowing white smoke. If your o ringe or throttle body were leaking it does not take much antifreeze mixing in to turn your exhaust white. If you are losing coolant and mixing with your oil the oil will turn a muddy brown colour quickly from the antifreeze. If the leak is somewhere close to the engine coolant entrance you may not notice a leak since the leak will only happen once the system is up to pressure and your engine is hot. The coolant can quickly burn off on your manifold and engine. You should however be able to smell the coolant burning. Hope that helps you.

Also check your water pump for a leak. have you noticed any squeeling noises coming from that area that may indicate the pump is failing?

Another note.....after you find and fix the leak, if it'* actually burning off, make sure you replace your O2 sensor. It won't like the antifreeze exposure.

Maybe way too simple, but did they check the radiator cap when they pressure tested it?

Update: So far nothing new! I changed the oil over the weekend and could not detect any water/antifreeze in the oil. I ran the engine to operating temp (T-stat open) next to my wife'* 98 non SC Grand Prix to see if I could detect any difference in the amounts exhaust steam. I could not detect a difference. I hung my head into and under the engine using big lights and did not see any signs of a leak. I also priced a pressure tester kit at NAPA and ran home when I could not find one under $100. I would like to run the tests myself. The coolant level in the radiator is closer to the top than before as if the hot/cold cycles I have been putting it thru are allowing the radiator to refill from the expansion tank as it should. I only drove the car about 20 miles and it is hard to detect any further coolant loss. I'll keep checking and let everyone know if I have a leak or if all this was my hyper imagination that something is going wrong.

I got 2 suggestions...

1) (not very likely, but worth the mention) Have you had any work done on your cooling system in the recent past? Possibly working out air in the system?

2) I did have a similar issue with my 95 SSEi once. I knew I was leaking coolant, but didn't know from where. I would be sitting at a stop light and see white smoke come up from under the hood. By the time I could pull over and pop the hood there was no trace of any coolant anywhere. I eventually found a hairline fracture in either end of my radiator. The crack would only seem to open when the radiator heated up. And due to the location of the cracks behind some frameing it was VERY difficult to see. The coolant was also burning off before it ever dripped down to the bottom of the RAD. I replaced the RAD a while back and the problem hasn't returned since.

BTW: I also had what seemed to be good line preassure, no coolant in the oil, or anything burning thru the exhaust.

UPDATE: Because of nasty weather the car has only been driven about 50 miles since the last posting and it has NOT shown a noticeable change in the coolant level. As soon as the roads clean up again, I'll put some further miles on it.