G
Guest
·Hi all. I have a tapping sound that sounds like it's coming from a pushrod. So, the other day I went to order new pushrods, but I have a choice of three: 9.56", 9.59", or 9.62". So I ordered one of each. I round-robined them through my driver side valve train, Dykem'ing the valve ends to see what kind of wear mark each length rod had the rocker arm making on the valve end. I figured the rod with the most centered wear mark would be the correct length to use (I mistrust the rods that are in place now, not to mention they are all somewhat bent).
I also tried to put just the long rod (9.162") in various places to take the slack that may be causing the tapping. No placement made the tapping stop.
I also tried using my mechanic's stethoscope in many places to find the source of the tapping. I couldn't isolate anything.
My findings were that:
a) I cannot isolate the source of the tapping
b) I found the long rods (9.62") to cause the least centered rocker-to-valve contact point, where the other two lengths were both more centered, yet indifferentiable.
So, I don't know whats tapping, and I don't think new rods will fix it. Does anyone have any ideas?
BTW: 390ci, hydraulic lifters, non adjustable rockers. Rocker faces slightly pitted (I'm poor), I don't know much about the internals.
I also tried to put just the long rod (9.162") in various places to take the slack that may be causing the tapping. No placement made the tapping stop.
I also tried using my mechanic's stethoscope in many places to find the source of the tapping. I couldn't isolate anything.
My findings were that:
a) I cannot isolate the source of the tapping
b) I found the long rods (9.62") to cause the least centered rocker-to-valve contact point, where the other two lengths were both more centered, yet indifferentiable.
So, I don't know whats tapping, and I don't think new rods will fix it. Does anyone have any ideas?
BTW: 390ci, hydraulic lifters, non adjustable rockers. Rocker faces slightly pitted (I'm poor), I don't know much about the internals.