Piston Slap in a 2.25

[msggunny]

Ok, i had my 2.25 rebuilt around 10,000 miles or so ago and now it has developed, by what my research has told me, piston slap. On start up there is a distinct but muffled metal tapping noise from the rear of the block. it gets quieter once the engine is up to operating temp, but it is still there. I have adjusted my valves so its not that. I would take it back to the dude who rebuilt it for me, but that was in Zimbabwe so that's out of the question. the pistons are .60 over and its all genuine LR stuff. when i tear the head off what do i need to look for? will there be a distinct gap in the block or piston or is it all in the rings? I am planning on tearing the bottom apart too to see if there is any undue wear on any of the rod bearings. Has anyone dealt with this? could i have misdiagnosed it? will i need a new piston(s) or just rings/bearings?

Thanks,
Richard
77 Series III 88

[evilfij]

Humm, doubt it is piston slap. I would think something is bad in the valve train. Rocker, pushrod etc. or you have messed up the valve adjustment.

Ron

[mfreeman]

Symptoms sound like a partially failed cylinder head gasket.

It might save a lot of grief and extra wrench cranking to check the compression in each cylinder first. Stray compression from one cylinder sneaking into the adjoining cylinder at odd times can create the exact sound you describe. Llow but similar compression values in adjacent cylinders is the indicator.

If the rebuild was a good one It's unlikely that the lower part of the engine is at fault ... check there last.

Good Luck

Mark

Series Vehicles, Range Rover Classic(s) and ....?? in Missouri