Could be. Look at all the parts the coolant runs threw. Some times it runs from the engine to the throttle body (Fast idle thermo valve) to the iac and back. Just depends what you have. If you get one coolant line mixed up with a vac line or have small cracks in coolant related parts or not sealing rite you can get coolant into the intake. If I remember rite some of the gsrs run coolant threw the intake gasket too. My look at that also.
I would be nice if you got a coolant pressure tester. I like the simple ones
http://www.stant.com/images/Stant/ezlit/12270Tester.jpg then you may be able to spot the leak. Plus use the proses of elimination by plugging and taking parts off. It has a little pressure gauge you can watch.
More then likely its something stupid like the wrong gasket thats how it always works out for me.