Just purchased a 97 GMC suburban k1500 4x4 5.7l and I was told it had a leaking water pump easy fix in about an hour... Well I replaced it and I still have a coolant leak. What I noticed was when I pressured up the system I hear air escaping somewhere around the intake but I can't find it. I used soapy water and still don't see anything bubbling? Fyi no coolant in oil and no pressure from a bad head gasket in cooling system. Is it bad intake gaskets?