KA Teardown Question (Rod knock/piston slap)

[Kinematics]

Originally Posted by Al_S14

piston slap is when there is excesive clearance around the piston ... as if piston is too small for the bore so it is slaping sides of the cylinder wall and not the head. this is common on some turbocharged engines(not factory) whose pistons make noise untill engine warms up and pistons expand.

i think you started your diagnostic process from end. shoudl have pulled the pan and checked rod bearings which is what the problem is. i have yet to see a KA which has stretched the studs enough to spin a bearing or stretch a rod(well this i never hear of period) - its almost impossible.I am certain its rod bearings that took a shit on you from from lots of miles or lack of oil.

Thanks for the advice. This is just a spare motor for me as I am swapping in a fresh one. I can't pull the entire thing out yet, so I'm just pulling it piece by piece for now.

I'll have to see what the rod bearings look like when I get that far, but thanks.

[ledzeppelin240]

Check the cylinders for out of round and if they are there was most likely piston slap in the cylinder. Check the piston for a collapsed skirt, which would cause piston slap as well as excessive clearance.

The absence of carbon or washed effect is from a coolant leak into that cylinder.

Check to see if the rod bearings have even load wear, also if you have a micrometer check to see if the rod journals and rods are out of round, or elongated.

[Kinematics]

I've got the motor pulled out and halfway torn apart, I have to wait on a crank pulley puller to get the rest out, but at least I know now what the issue is with the motor.


Lots of metal shavings. Rod #1 has about 3-4mm of play to it on the crank.


Here's the main piece I've found so far. Looks like rod bearing to me.

I'll probably add a few more pictures once I get the oil pump off and the rest of the assembly removed. Thanks for reading.