A-Dub

iTrader: (6)

My wife drives an 00 Wrangler inline 6 with 60k miles. Brought it home today, said it was running funny. I drove it. It makes no power, sounds and performs like it has atleast 1 dead cylinder. I tear into it, eventually do a compression test. When I plugged the the tester into #3 you could hear the pressurized air rushing into cyl 4 and vice versa. Stuck and plug in #3 and the tester in 4 and the noise went away, registered 30 psi. Swapped spots with the same thing. That screams head gasket to me, but I have no other symptoms other than dirty coolant (not milkshake though). Wife also filled it up with gas today and she isn't 100% positive it was acting up before fill up.

Posted it on a jeep page and got a couple head gasket responses and a couple stuck valve responses. Any engine guys have some good advice on how I could narrow it down before tearing the engine apart?