In <list-1260695@skylee.com> someone harrumphed:
>I have an M109A2 shop van (LDT 465-1C) that runs great when it is first
>started. Once the oil pressure is up, it starts making a loud hammering
>noise. It is so loud that I can't tell if it is coming from the top or
>bottom of the engine. The fact that it doesn't start up for a minute or
>two after the engine is running makes me think that it is not a rod. It
>seems like a spun rod bearing would make noise from the instant the
>engine started.
Spun Rod bearing can wait 10 or 20 seconds of idling before you hear a
gentle 'thunk' and then the much louder rod knock. In my case, 400 cu inch
Chevy smallblock, there is no rod knock, usually, at startup, since the
bearing clearances are correct. But then the bearing decides to spin into
a new position (gentle thunk) and now there is plenty of bearing clearance
and the knock stays with you until you stop the engine. When the engine
dies or else during cranking, the bearing snaps back to 'normal position'.
Classic case. I haven't fixed this engine yet; too big for the M37. What
does one do with a fresh 400 these days??
-- ----------------------------------------------------------- wwd@netheaven.com -----------------------------------------------------------
This archive was generated by hypermail 2b29 : Sun Sep 02 2001 - 11:15:41 PDT