I've got a 230 inline six motor with a horrible backfiring issue, and I've come up with a possible clue as to the problem. My cylinder 6's intake valve is not opening nearly as much as the rest of the valves, and the pushrod is barely moving at all. I want to say this is a possible cause of the problems I've been having, but I'm not sure if it's a stuck valve, dead lifter, weakened spring, or something else that's causing it. Also, I need to know -depending on the cause- if the head needs to be pulled or not. Here's a video of the valve with the cover off:
https://drive.google.com/drive/u/0/my-drive
Hello,
Looking at he very short video you include it looks like the camshaft at the very back is worn,
Its not opening the valve sufficiently, There is an inspection plate on the side of the engine
You could remove it and have a look, (NOT with the engine running)
It could also be the cam follower disintegrating,
Also there seems to be a lot of back pressure (smoke) coming up from the crankcase.
It doesn't look good for this engine's health.
All the Best.
@dvkala
Could the back pressure be a PCV valve issue? Should I replace the lifters before assuming its a worn cam lobe? Also, I've got some longer videos if you need them. Thanks.