Valve Train Clatter

[debugjaws]

1995 YJ 2.5L 4 cylinder, 119k miles. Noticeable Clatter occurring on "deceleration", not acceleration. This seemingly occurs at the #2 and 3 cylinders. I can reproduce in the shop by manually throttling and listening with an automotive stethoscope. Thus far I have replaced lifters, rockers, push rods, cam, timing chain, gears, and distributor.

Not sure what else could be causing this other than maybe the noise is "normal"(?). Last remaining components in the head are valves, guides, and seals. This motor runs solid, and the noise is definitely not coming from the block. Anybody else have this issue or one similar?

 

[Flyer58]

Are there any changes to the oil pressure when decelerating? Connecting rod bearing wear may be the cause. Get up to speed and take your foot off the gas so you get a good long deceleration time and look for pressure changes or other signs.

 

[deadpool1]

rod bearings do a double knock and very loud. , mains a huge deep boom under loads.
yes finding noise is not easy.
record the sound to MP3 file and share it , if possible.?

one good thing , it fails parked, making at 10x more safe to find.'

try different VIS oil,. 10w-40 ?
make sure oil pressure is at spec, at noise, De-accel.
does it fail engine cold and warm and hot ,all 3>?

where the new lifters ,pre-primed per the FSM before put in?

cylinder leak down tests pass?