low engine rpm knocking?

[DREWHALL]

piston slap? is it worse when the motor is cold?

This is my guess. Mine's starting to do it

[TrentW]

I third that. E motors are known for this. My wife's '88 Seta does it intermittently--but only until next year when I swap in an M20b25. :)

[Eecen]

When you drain your oil do you see any copper'y colored metal flakes? Ever cut open one of your used oil filters?

[trevor144]

piston slap? is it worse when the motor is cold?

No not really. It's more of a thud. My old e30 made a similar sound as this one but only under load, turned out to be a loose muffler.

[bddog]

Short broomstick to your ear. Works for valves , bearings, etc.

[Jaxx_]

Short broomstick to your ear. Works for valves , bearings, etc.

or hose