'02 sl2 knock
 

got serious noise at idle, rev it up, it goes away, some times, the stethiscope gives loud noise at #4 cyl head, less up front, very noisy from the oil; pan, no metal in oil, havent removed the filter yet, had the v-cover off running, no valves looked stuck, no lash adjusters looked loose, running, just very loud knocking that changes w/rpm joe

guess crank bearing--gotta look

brg
 

after i check oil pressure tomorrow, ill pull the oil filter to investigate, no metal in the oil at all, a bad bearing would contaminate the whole pan, right?

or rod knock

not a knock expert -- seems to me if it is in the bottom end, you'll need to drop the pan to investigate.

Did the oil get too low?

?? possibly a wrist pin issue ??

well, i pulled the oil sender, started it up, and it jumped passed 30 psi, with a mechanical gauge, i can rule out lash adjuster pressure, car did not run out of oil, is there a wrist pin/piston issue with these motors? i cant imagine the crank or rod bearings being suspect, the revving up to the point where it quits knocking is making it hard to isolate, im going to split the oil filter next, check for metal, none visible on the stick, if anything let go, it would present contamination, ill post after i dissect.

?? Wrist pin issue with the engine (as a class problem) ?? Normally, no - not that I'm aware of