1990 Legacy GT Engine Issues

[eXpLoSiV]

I have a 1990 Legacy Turbo Wagon, and as of the past week it hasnt been running quite right.... it has two problems that i have picked up on myself, and i havent taken it to the machanic yet.
when the engine is running it makes a rattling sound that when i listen clos sounds like its coming from one of the cylinders, also when driveing the turbo sounds like its spooling and lets off blow off valve but quieter and not boosting at all. if anyone might possibly know what the problem is input would be much appriciated.
i have a feeling that the turbo may be stuffed, but im no mechanic