Head gasket question

What’s the chances I have a failed head gasket even though the truck never overheated.

Some Symptoms…
Runs rough
Misfire code
No compression in one cylinder
Very small puff of gray smoke a couple days before the running rough and the misfire code


2007 4.0 with 197k it…

It’s already at the shop…. I’m just overthinking things this weekend because I wont know until more tests Monday

 

It's possible to have a failed HG without overheating. Lot's of posts here about it. Are you losing coolant?

 

It doesn't really matter if the head gasket has failed. With no compression on one cylinder - which can have may causes - that motor has to come apart or be replaced.

 

Odds of a headgasket failing and causing no compression on a single cylinder with no other symptoms I would have to say highly unlikely.
A simple leakdown test would tell you where it's going.

 

I recently replaced my head gasket, I started smelling burnt oil (the oil was dripping onto the exhaust manifold). I never had an overheating issue, but my lil 4banger has been doing fine since replacing the head gasket.

 

You've got no compression on a cyl. HG doesn't really matter if the head has to come off