Mysterious knock between #4 & #6 cylinders
#16
Re: Mysterious knock between #4 & #6 cylinders
As stated above,I would not run a motor without the pushrod..I would be concerned that there is no oil coming out of the rockers while the valve cover is off..Maybe I missed it but,what is your oil pressure at?In the first video the sound did change when you moved to the front of the car,to me it sounds like a rod knock,if I had to guess I would say #6 rod is spun.I have a motor here that I just tore down and it spun #6 rod..For your sake I hope its a bad lifter.
#17
Re: Mysterious knock between #4 & #6 cylinders
As stated above,I would not run a motor without the pushrod..I would be concerned that there is no oil coming out of the rockers while the valve cover is off..Maybe I missed it but,what is your oil pressure at?In the first video the sound did change when you moved to the front of the car,to me it sounds like a rod knock,if I had to guess I would say #6 rod is spun.I have a motor here that I just tore down and it spun #6 rod..For your sake I hope its a bad lifter.
#19
Re: Mysterious knock between #4 & #6 cylinders
Again, I would like to emphasize that I am a shadetree mechanic, not ASE certified, etc. I offer this advice as the direction I would follow and that which I have learned from practical experiences.
Charlie
Last edited by charliediss; 08-28-2011 at 12:23 PM.
#20
Re: Mysterious knock between #4 & #6 cylinders
New pushrods on #6 no change in noise from day 1 will investigate oil for shavings. Hoping no shavings means lifter collapsed. Again oil pressure steady at just above halfway.
Last edited by ctowns77; 08-28-2011 at 02:49 PM. Reason: add
#21
Re: Mysterious knock between #4 & #6 cylinders
Looks like to me the knock(first video) is timed with the movement of the rockers. I'm betting bad lifter(s) or no oil getting to one(or more) of them for some reason.
Here is rod knock...
http://www.youtube.com/watch?v=WA4G_LDEflo
http://www.youtube.com/watch?v=MQwem...eature=related
Edit:
After listening again...I'm not so sure now. Best thing to do is pull the intake and swap out the lifters. If that does not work, then pull the oil pan and check the rods. Or...grab a mechanics stethoscope. Start probing the engine with it. You'll find the source.
Here is rod knock...
http://www.youtube.com/watch?v=WA4G_LDEflo
http://www.youtube.com/watch?v=MQwem...eature=related
Edit:
After listening again...I'm not so sure now. Best thing to do is pull the intake and swap out the lifters. If that does not work, then pull the oil pan and check the rods. Or...grab a mechanics stethoscope. Start probing the engine with it. You'll find the source.
Last edited by ACE1252; 08-28-2011 at 03:30 PM.
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