99 3800 startup trouble and rough idle
 

I've owned my Camaro for two years, and it's always had trouble starting. If it has been sitting for more than a day, it starts fine, but if it's only been a few hours, it will take a long time to start and idle rough once started. The problem is usually fixed by turning it off and back on a couple times. I replaced the air filter and cleaned the MAF, but the problem persisted. When I was cleaning the MAF, I noticed coolant had pooled up in the throttle body, so I replaced the PCV valve hoping that was the issue. I also took the throttle body off to clean it, and coolant was pouring down the front of the engine. While I was looking around inside, I noticed thisAttachment 46214
Is that hole supposed to be there? It looks awfully jagged. If it isn't, where is a good place to find a new intake manifold? I've looked on ebay, but only found 1, and I don't really want to buy a used one without seeing it in person first.
If it is, what's the next step in diagnosing this problem?
Thanks for the help.

I find it very hard to believe that is your issue. In 30 years in the automotive world I have never seen a failure in an intake. I would guess that was a ask cast feature that did not get cleaned up. The build sooth is not helping. You would want to see coolant stains around anything suspect. I would guess its you intake gasket as it is a very common failure point. A coolant pressure tester may help you fine it. Find a local you pull it lot. Since intakes almost never fail they can be bough cheap. I sold one off a 42k 2002 with the drive by wire throttle body, intake and injectors for $20+shipping 8 years ago.

Check your oil and make sure there is no coolant in it. If there is DO NOT drive it.