Bad lifter causing misfire?

[Willytime]

2000 4.0 - Been reading a lot of threads on here but want to get some thoughts. Out of the blue on my way home, I got this bad ticking sound. Hope the attachment works. I changed the oil about 2000 miles ago with Mobile One High Mileage. I had a CEL on for evap leaks, but hadn’t got to that yet. Rechecked OBD after the ticking and now I have a cylinder 3 misfire as well. I changed my plugs, rockers, and push rods (nothing bent) to take care of the easy stuff. Changed oil and threw in Marvel Mystery Oil. Still sounds terrible - took it around the block but worried I’ll do more damage. Thinking bad lifter causing sound and misfire?? I know these heads can crack between cylinders 3 and 4. No sludge or buld-up under the valve cover. Do you agree it’s a bad lifter? Never changed a camshaft - is that necessary when doing lifters? Thanks all.

 

[jeepguy03]

Have you done a compression test? I had a 2000 4.0L in a Cherokee, and it would have occasional misfires on one cylinder. Turned out to be a broken valve spring.

 

[pagrey]

Ya, something sounds broken like @jeepguy03 says. For that much rattle I'd think something under the valve cover would be obvious as you rotated the engine.

 

[Gilaguy23]

Yes, if the lifters are swapped out rule of thumb is the cam should be as well.

 

[Willytime]

Just closing this thread out in case anyone comes across it and are hearing this noise. Bad news - piston skirt failure. Shattered pieces in the oil pan. Rather than tear it apart, I ended up putting in remanufactured engine. Good luck if you have these sounds in your Jeep.