Originally posted by: GalvanizedYankee
It is with some reluctane I post. I'm not going to get in a running gun battle w/anyone of the many ppl that just want to increase post count.
Listen to Mr. fire he knows much of what he speaks.
The price must be good or you would not persist 😉.
My test for rod bearings that has served me well for >40 years. With the engine fully warm, drive with the car in 2nd or 3rd gear up to about 4500rpm at full throttle then reduce throttle very quickly to the point of coasting. The unloading of the pressure on top of the pistons will cause a loose rod bearing to clatter. The clatter maybe slight, so be sure the windows are up, radio off and no heater/ac blower is on. A rod bearing maybe a $15 part but it is not like installing software. If it were my car and I was going to open it up, I would change ALL the rod & main bearings. With prolonged use a loose rod bearing can/will cause the rod journal of the crankshaft to wear *out-of-round*, The tolerance is quite small, I would guess <.00075" and journal taper at <.001. If a new bearing is put in and the crank is out of tolerance, the repair will not hold.
1 Piston slap has a hollow sound and sometimes some oil smoke.
2 Main bearing knock is most apparent under heavy load, like pulling a steep grade.
3 Valve lifter clatter will go away right after start-up and will not accure at a shift point over-run as a rod knock will.
4 Quick test for drive shaft on RWD car. Foot on brake, engine at hi-idle, shift from driove to reverse without changine throttle setting. If there is a clunk, check drive shaft.
5 CV joints that are bad will let you know when cornering.
Gobadgrs, try Google for diagnostics. Someday we will have remote assist for car repair.
Good Luck, jj
