Hi All,

After much delay I finally got a rebuilt head onto my B230F. The head sounds smooth and the crazy rattling I heard beforehand is gone... So the original head's valve train must have been fried.

But now that the head is quiet there is a distinct knocking sound. Of course,
my first guess is piston slap. Engine has about 190k miles on it. But after some research I'm wondering if it isn't rod knock...

The knock is there right when the engine starts up. More pronounced as throttle is lifted off, i.e as the engine drops down in rpm. It is audible when the motor is up over 3k rpm and doesn't really seem to drop off after the engine is warmed up.

So how can I tell the difference between piston slap and rod knock?

I realize I can drive a long time with piston slap but how far could I go with rod knock?

Thanks,
Bert