So i finally got around to removing the intake manifold on my 89 sc with 245,000 miles. I had coolant in the oil, a misfire, and my boost gauge was reading 10 vacuum at idle. After removing the manifold i dicovered coolant underneath my intake manifold. And there was a puddle of coolant near cylinder 1. Is it possible that a bad head gasket can cause the coolantto get undernearth the manifold? Also it is possible that a head gasket could cause all these problems? My intake manifold gaskets looked a little warped but nothing major. I will upload a picture of them.