2004 Disco II 139k on truck, roughly 40k on engine

Relatively new here, and yes I've used the search function on the P0306 and what all potential solutions are...backstory on the truck

Bought it about 8 months ago after it had been sitting for a year or two inoperable. Have done various things to it

Dealership had to get a new key/drivers door handle and unlock as it was triple locked

Since then...

New head gasket/machined head on driver side after over heating from the plastic Y connector cracking and puking fluid out while driving
new spark plugs all around at same time
new exhaust manifold gaskets, also downpipe flange gaskets replaced
radiator checked out as good, but all hoses replaced and new aluminum Y connector replaced
heater plate replaced
alterrnator replaced
AIC Valve replaced
new starter

Mechanic said the coils and wires were fine when in there doing the driver's side gasket. Also said the engine is incredibly clean. This is an AB rebuild engine, installed in 2012 and only has around 40k miles on it.

Here's where I'm currently at. We had a freak ice storm in Texas this past week and I drove the rover with ZERO issues. Got me through some areas that I needed it to, but didn't dog it out or beat it to death. Took any off roading slow and practical. Got in the truck two nights ago to take the kids to get some food. Heard a slight ticking from the passenger side of engine bay, and as the night went on it got just a bit louder. You can hear it more under acceleration. I figured the downpipe isn't holding as one of those bolts has snapped off.

We got in yesterday afternoon to run around, and the slight ticking had turned into what sounded like someone beating the engine from within with a hammer. The exhaust smell is very present, but apart from that flange I can't detect any other leaks. The SES then came on and Ultragauge threw a P0306. SES will flash intermittently then stay on.

The sound reminds me of the blown head gasket sound from the driver's side, but I show no signs of coolant loss, frothy/milky oil, or coolant behind that number 6 plug.

Where should I start next? On a scale of 1-10, I'm about a 7 on what I can mechanically do in my driveway. I did outsource the head gasket to a pro, as I didn't want to attempt that.

 

So it sounds like the head gasket blew on cylinder 6. When it happened to my daughters my wife said her car sounded like a helicopter. You should be able to feel it if that is the case. Put your hand down by the exhaust manifold and you will feel the pulses.

 

it does sound very similar to when the drivers side blew. Was hoping this wasn’t the case with no loss of coolant, but fearing the worst here.