1994 Olds 88 3.8 V6
A while back I posted about loud banging while starting, and after attending to a couple of other matters, I am back with more information.
I am still trying to figure out why after starting sometimes something knocks REALLY badly 2-3 times (like a rod is about to punch through the block). Once the engine is at idling speed, all is well, and it doesn't do it every start-maybe 1 out of 5.
It'* LOUD and dramatic enough it sounds and feels like someone is striking the engine block w/ a BIG hammer, and the engine mechanically pulses each instant it knocks (as if it is hanging up on something mechanically for a brief instant). Once the engine is running, it sounds smooth like a Swiss watch as well it should w/ 60k original miles on it.
My feeling was that it was a loose bolt in the bell housing that occasionally flips and gets caught between the torque converter or the flex plate and the housing itself, then flips out of the way again.
Yesterday, the starter quit, giving me the opportunity to examine. Odd that at 60k miles since new, the solenoid quit (no click, but there is voltage at the solenoid terminal, so it'* a dead solenoid for sure).
I dropped the starter, and it looks fine, with the starter shaft and teeth, and the teeth on the ring gear in perfect condition all around (though obviously I am going to replace the unit).
I carefully examined inside the bell housing as best I could with the inspection cover (where you get at the flexplate-to-torque converter bolts), and I can clearly see an area around the T/C shiny steel (outboard of the ring gear teeth) where something has been rubbing, and there are some shallow "dents" as well that I imagine are caused when it "bangs" loudly. The dents look like someone took a punch and hammered some shallow (maybe 0.005") divots into the T/C.
I inspected carefully w/ a flashlight, and probed around w/ a magnet wand, and had someone turn the crankshaft while I looked and probed in the bell housing as well as I could, and I could find absolutely NOTHING down there at the bottom where one would expect to find something loose like a nut or bolt floating around that could sometimes pop up and into the way.
Any ideas what it could be causing this, or what could be loose and getting into harm'* way at times?
The rub marks are all around the radius shown with a RED arrow in the photograph that is at this Link: 2013-06-29_0929 - bobinyelm'* library
The photo is taken looking up and slightly back into the inspection area (big plastic cover removed).
The narrow rub/scratch mark all around the T/C is not that shiny in the photo, and the small shiny indentations (divots) are on the other side of the T/C (but in the same area the arrow points to). They are all in the radius of the T/C right at the arrow-point.
Any ideas or suggestions most welcome as I am sure that at SOME point, whatever it is may do some actual damage to the T/C or something else.
Any other way to get at that area to inspect w/o pulling the engine/tranny?