I posted a thread on here about a month ago about some weak compression in cylinders in a '91 mustang gt. I have now ran my own compression check and found that the two weak cylinders are side by side. #1 and #2. So my question is, is it possible for a head gasket to blow between the two cylinders so when the pressure builds it leaks into the other cylinder? When i get off tonight i'm going to put a lil bit of oil and see if that brings up the compression and if it does then i know its the rings but i'm just trying to cover all the bases before i start looking into an engine rebuild. It does not smoke however it does loose oil and coolant (haven't as of yet found a leak in the coolant sytem that i can see) I have changed plugs, plug wires, cap, rotor, and coil. the old plugs had a red or rust tint to them when i pulled them out. Once again i apologize for being such a noob at all this stuff just trying to save some money by avoiding a rebuild that is not needed. Thanks for looking