ASE A1 A-1 Engine repair double knock piston pin vs rod knock diagnostic.

This video is to help you with your ASE A-1 Engine repair certification test. The question is about a double knock that becomes louder when the cylinder is disabled. Piston noise becomes louder when the cylinder is disabled while rod noise becomes quieter.

[@DELTRANIO99]

Great vid does a slight wrist pin knock more pronounce during acceleration or a steady RPM in the 2000s ?

[@southfloridatechnicaltrain2589]

It should knock more with less load and while revving the engine.

[@DELTRANIO99]

@@southfloridatechnicaltrain2589 Thanks for the reply back much appreciated ,,Well if I keep it at a steady 2000 RPM and accelerate to like 2500 2700 RPM its like a hear a slight growl,,, The engine is a 6.0 LQ9

[@southfloridatechnicaltrain2589]

@@DELTRANIO99 its a camshaft most likely I have done many.

[@DELTRANIO99]

@@southfloridatechnicaltrain2589 Do You think its bad ? It seems to run good

[@southfloridatechnicaltrain2589]

@@DELTRANIO99 I have seen a bunch of cam problems on the 4.8-6.0 chevy. It will eventually cause a misfire on #7 or #8

[@thesetruths1404]

Howdy. I have a new-to-me 1998 Nissan Pathfinder 4x4, automatic, 3.3L VG33E 4th VIN digit "A" motor, made 10/1997. It has one or more bad piston wrist pins, and a confirmed bad crankshaft due to excessive bearing failures from oil loss. Does anyone know if the pistons in a 1996-2004 Pathfinders, QX4, Frontier, or Xterras can be removed and reinstalled through the bottom of the motor (oil pan), with the motor still installed? I also have a bad crank so I have to have it removed and machined too. The rest of the motor is clean, no oil burning, and low miles (165,000). I hate to swap it for an unknown possible problem motor if I can do it this way instead.
I haven't been able to find anyone online who has accomplished this, but maybe it's not possible due to clearance or whatever. Do ya know, or take a guess, if ya been under one of these models with the oil pan off and crank out? Thanks much!

[@southfloridatechnicaltrain2589]

I have never seen any engine where you can do pistons from the bottom. I am not saying they do not exist but in 30 years building engines I have never seen it once. Even if I could I would just pull the engine. You need to keep everything clean during a build and if you had bearing failure you need to go through everything not just the crank and pistons. Plus you do not know if the piston smacked a valve.

[@thesetruths1404]

@South Florida Technical Training thanks! Yeah I confirmed it was not possible. Crankshaft mounting steel gets in the way.

[@Interestingstuff6909]

Remove spark plug, crank by hand, push down with tool on pistons down stroke, if knocks piston wrist, again if knock on up, divorce your spouse.

[@southfloridatechnicaltrain2589]

not a bad trick but this is an ASE test question tip.