Hemi Valve Spring Maybe?

[AvantiHauler]

2012 Ram 1500 with 5.7 Hemi 210,000 miles. Threw a P0306 Cylinder 6 Misfire but it was not noticeably running bad.
Mechanic ran through the diagnostics and ruled out spark plug and coil which were fine. Next they checked for valve blow-by (maybe wrong terminology - valve was leaking?) and found exhaust valve was the issue. I continued to drive it, gingerly, and it ran ok for several weeks until I had to accelerate really hard to avoid an accident. Immediately after that it started running with a noticeable misfire, basically running on just 7 cylinders.

Sounds like it is not uncommon for the Hemi's to break valve springs? Would it make sense that I had a weak valve spring causing the occasional misfire and engine code, and when I had to jump hard on the throttle the spring just broke?

Is it worth having my mechanic pull the valve cover and just replace that cylinder's valve springs, even if they dont find a broken spring? I would be really happy if I could just get another year/10-12K miles out of the truck for a sub $1K repair. Worth taking a shot?

Any advice or info appreciated.

 

[Burla]

If the mechanic is saying it was a valve, why are you asking us if you should tell him to pull the valve cover? Shouldnt he be telling you that? Yes it is very common at 200k miles to lose a valve spring, if so it is a lucky break, have him replace all the valve springs on that side, if he gives you crap about replacing all of them, chose another mechanic. Yes replace all springs. Better yet, ask mechanic what the cost to diagnose this is.

It could be a cam lob, and if so it wont make 12k miles, probably not 1k miles.

 

[Sillygoose]

a cam & lifter job is most likely in your future.

 

[Daw14]

Until the valve cover comes off it’s just a guess .