I just inherited a 91 cherokee sport 4.0 and i know it needs a head gasket set but when i did a compression test, cylinders 1,2,3, had nothing and 4,5,6 was bouncing between 25 and 60 psi. I added oil into the plug hole and it did not change. Should i go ahead and put the gasket set on or have the pistons and rings checked?

 

Are you going to be doing the head gasket? I would just pull the head and see whats going on. See how bad the gasket is and if your pistond are messed up at all. JUst take and look and let us know what you find.

 

Thank you for the advice.