For the past several years, my 87 2.1 engine has had an internal rattle.
Kind of sounds like a marble vibrating near the distributor. It rattles
a lot faster than a loose valve lifter. Maybe twice a revolution instead
of once every other revolution. This is an engine that I totally rebuilt
about 6 years (60k miles) ago. It had spun a rod bearing. I put in a set
of rebuilt 1.9 rods, reground the crank, new rings, etc. It runs great,
but the oil pressure was a little low. First I just shorted out the high
pressure sensor, but started using straight weight 40w oil for 9 months
a year. That keeps the buzzer off. I wouldn't be surprised that I
boogered something up in the assembly, but if it is a terminal error, it
sure is getting there slowly.
So, anyone have any ideas what might be the source of the rattle? I've
pretty well eliminated all the external sources.
Except possibly the plastic oil vent tower. Is there anything in there
that can get loose and rattle?
My other guess would be the distributor drive. Is there supposed to be
only one thrust washer at the bottom? What determines the end play of
the drive? (One thing that makes me wonder is that the timing seems to
dither when you check it with a timing lite. Maybe moves around 4
degrees or so.)
If the drive had excessive end play and was smacking up against the
distributor every half turn, that might be my sound! It has about the
right timbre or tone, if you know what I mean.
Any suggestions?
Al Brase
87 GL, 80 westy, 56 pickup