get your compression checked...
My step father just had a problem on his EH with RB30ET in it,
First real drive and it blew the head gasket, once we opened it up it had obviously happened before he got the motor,
All the bore had rust marks on it and starting to pit...
the mechanic was telling him it would be alright because it was only 2 cylinders down and only 15psi...
Also check ur oil, if it's milky ur getting coolant into ur oil...