perhaps some of you remember me posting about a chevy 3.4l that lost a intake manifold gasket and gargled some coolant for a bit. the first Oil change had some metal in it, so i've been changing it every 1k miles or so. very light sludge continues to come out of it. last weekend, i changed the oil (it takes about 4 quarts) with 10w30 and replaced one of the quarts with 15w40 diesel oil (i don't care if it doesn't "clean" by itself, i just want it to hold the sludge in suspension). replaced with purolator oil filter and drove about 30 miles that day. no problems......(JIC, i don't usually give it a full crankcase of oil. if 4 bottles puts it to 1/4 or 1/2 above min on the dipstick, i don't bother adding any more because i change the oil so much that i don't want to waste it). i "thought" i heard piston slap in the motor the day before the oil change. anyone want to tell me what piston slap sounds like, just so i'm sure? at any rate, my mother calls me and tells me that her husband said that the engine is now knocking (she says you can't hear it from inside the car). he might be hearing the same "slap" i though i was. they aren't driving the car anywhere, and i can't get a straight answer from anybody as to how much oil is in the crankcase right now. i'll be man enough to admit it if i didn't tighten the sump bolt enough, or left a filter gasket on there, causing it to lose oil, but:

1. nobody can tell me how much oil is in there right now
2. nobody has bothered to check the carport floor for leaks
3. i drove the thing for 30 miles the night of the change...no weird noises,