Re: Locked-up oil pump

#1

Michael Bonnice wrote:

Quote:

I'm looking for the source of chunks which locked up my oil pump. The
motor is a 302 from a '77 Mustang, although it is in a '65 Fairlane. The
engine was rebuilt 10 years ago, 43K miles ago. I'm going into lots of
detail below because it helps me think through the problem. Perhaps you
can enlighten me on some points.

Here's the whole story. A week ago I took the car out for a drive. Two
or three blocks from home, the oil light came on. I pulled over and
checked the oil level, it was two quarts low (I've been neglectful of
maintenance, I guess). I called home and my son brought me two quarts.
I added the oil and started it up, but the oil light stayed on. I
drove the car home slow, backed it in the garage (lifters were clicking
by that time).

I pulled the distributor, drained the oil, and dropped the oil pan. The
oil pump drive shaft was twisted and sheared. The pump wouldn't rotate.
On disassembly, I found black chunks in the gaps between the rotors.
There was a smashed chunk compressed in the tightest spot between
rotors, but it wouldn't smash any further so the rotors locked up.

Chunks aren't supposed to get through the pick-up screen, so I looked
closely at the screen. There was a gap, under the "button" at the
center of the screen. In fact, another chunk was stuck in the gap, it
was slightly too big to fit.

In the bottom of the pan there were a few chunks, not much.

I cut open the oil filter, there were no chunks there.

There were two kinds of chunks in the pan - hard, black, glassy chunks
and black crumbly chunks. I think the crumbly chunks were cork or RTV
from the oil pan seal. I don't know what the hard, glassy chunks are.

The chunks in the pump were of the hard, glassy variety. They are
brittle, perhaps 0.050-0.070" thick. There was a large chunk in the
pan, same thickness, oddly shaped, perhaps 0.250" square. What's wierd
is it has some curvature, like it is from a piece of a broken glass tube
about 3/4 inch diameter. These chunks can be broken fairly easily; they
don't crumble but they shear when you twist or press them or poke them
with a dental pick. There is no damage to the pump because the chunks
are softer than the rotors.

The chunks are not pieces of piston rings, nor pieces of metal or actual
glass. On the large chunk, on the outer surface, under a magnifying
glass the surface has light scoring in the circumferential direction.
The corners of the edges look like they may have been sharp at one time,
but had become rounded. The corners of the chunks in the pump were
sharper.

Evidently, the chain of events started when I accelerated with a
nearly-cold engine (its 50 degrees in Phoenix these days) and with a low
oil level. Did this make it easy to pick up chunks? Did it generate
the chunks? Why didn't it eat the chunks sooner? Either the chunks
just now dropped into the pan and got sucked up, or they've been there a
while and just now got sucked up, maybe because the hole in the screen
just now opened wide enough, or the chunks just now got small enough to
fit throught the hole in the screen

I could get running again by replacing the pump drive shaft and the
pick-up tube and screen to get a screen having no holes, but this
doesn't eimininate the source of the chunks. Will there be more chunks?

What kind of chunk is shaped like a piece of curved glass? Did it come
from under the valve covers? From behind the front cover (in the region
of the cam drive)? I can't imagine it came from the clinders, because
these chunks would not fit the clearance between cylinder and piston.

Are these chunks a coating of some sort, perhaps building up over time
and finally breaking loose? Nothing inside the surface of the oil pan
looks like this, nor does anything in the bottom of the block or
cylinders. Maybe they fell off the surface of the valve covers or some
other surface. I can't see inside those covers unless I remove the
covers or get a boroscope.

So, any tips?

Mike

Plastic timing gears, maybe?

Rob

#2

trainfan1 wrote:

Quote:

Plastic timing gears, maybe?

Rob

No, I doubt it. Firstly, if I remember, the gears are metal. Second,
the shape is different. But the pieces do remind me of something
plastic which, when hit while cold, would tend to shatter as something
brittle.

The stuff is also like bakelite. Unless you are pretty old, you might
not remember that stuff. It is a hard brittle plastic or glass
material. I had a little 45 RPM record player as a kid, the case was
made of bakelite. There are probably bakelite parts in a 60's Mustang
(connectors, maybe?).

Mike

#3

Don't discount timing gears..... the OEM style replacement cam gear will
likely be aluminum with a hard plastic coating. This coating can and will
break off in little chunks.Another possibility may be valve stem seals....
the old black umbrella seals were known for baking as hard as rocks.

Since you have the pan off, it should be relatively easy to check timing
chain lash.

"Michael Bonnice" <mike.bonnice.no.spam (AT) pobox (DOT) com> wrote

Quote:

trainfan1 wrote:

Plastic timing gears, maybe?

Rob

No, I doubt it. Firstly, if I remember, the gears are metal. Second, the
shape is different. But the pieces do remind me of something plastic
which, when hit while cold, would tend to shatter as something brittle.

The stuff is also like bakelite. Unless you are pretty old, you might not
remember that stuff. It is a hard brittle plastic or glass material. I
had a little 45 RPM record player as a kid, the case was made of bakelite.
There are probably bakelite parts in a 60's Mustang (connectors, maybe?).

Mike

#4

Jim Warman wrote:

Quote:

Don't discount timing gears..... the OEM style replacement cam gear will
likely be aluminum with a hard plastic coating. This coating can and will
break off in little chunks.Another possibility may be valve stem seals....
the old black umbrella seals were known for baking as hard as rocks.

I'm voting for the seals, now, based on your original description... but
are they small enough to travel through the oil return passages in the
heads & block?

Rob

#5

I had the plastic coating come off the timing gears in a '76 302 which
resulted in a different problem, the chain skiped teeth. I read the orginal
post and the first thing that came to mind was that plastic. Open the timing
cover and take a look at the gears. My vote's on that plastic.
--
Mike
Silver 10th Anniversary Cobra Coupe
---

trainfan1 wrote:

Quote:

Jim Warman wrote:

Don't discount timing gears..... the OEM style replacement cam gear
will likely be aluminum with a hard plastic coating. This coating
can and will break off in little chunks.Another possibility may be
valve stem seals.... the old black umbrella seals were known for
baking as hard as rocks.

I'm voting for the seals, now, based on your original description...
but are they small enough to travel through the oil return passages
in the heads & block?

Rob

#6

I'd go with the valve seals. If they were rubber to start with. Especially
if the engine has overheated or ran hot for a while. Its happened to me 20
odd years ago.

If it was an original 77 engine I'd agree some of the larger chunks could be
from the nylon cam gears that were used back then, but I've never seen
pieces from them small enough to get thru the pickup screen. They were
"natural" or opaque white in color.

Check the bearings front and rear for scoring. There probably won't be any
to speak of. Replace the valve seals. Clean or replace the pump. Its a good
time to switch to a high volume pump if you choose to replace it. They come
with the drive rod. (or did)

Wayne

"trainfan1" <lmsearing (AT) usdatanet (DOT) net> wrote

Quote:

Jim Warman wrote:

Don't discount timing gears..... the OEM style replacement cam gear will
likely be aluminum with a hard plastic coating. This coating can and
will
break off in little chunks.Another possibility may be valve stem
seals....
the old black umbrella seals were known for baking as hard as rocks.

I'm voting for the seals, now, based on your original description... but
are they small enough to travel through the oil return passages in the
heads & block?

Rob

#7

"trainfan1" <lmsearing (AT) usdatanet (DOT) net> wrote

Quote:

Michael Bonnice wrote:
I'm looking for the source of chunks which locked up my oil pump. The motor
is a 302 from a '77 Mustang, although it is in a '65 Fairlane. The engine was
rebuilt 10 years ago, 43K miles ago. I'm going into lots of detail below
because it helps me think through the problem. Perhaps you can enlighten me
on some points.

Here's the whole story. A week ago I took the car out for a drive. Two or
three blocks from home, the oil light came on. I pulled over and checked the
oil level, it was two quarts low (I've been neglectful of maintenance, I
guess). I called home and my son brought me two quarts. I added the oil and
started it up, but the oil light stayed on. I drove the car home slow,
backed it in the garage (lifters were clicking by that time).

I pulled the distributor, drained the oil, and dropped the oil pan. The oil
pump drive shaft was twisted and sheared. The pump wouldn't rotate. On
disassembly, I found black chunks in the gaps between the rotors. There was a
smashed chunk compressed in the tightest spot between rotors, but it wouldn't
smash any further so the rotors locked up.

Chunks aren't supposed to get through the pick-up screen, so I looked closely
at the screen. There was a gap, under the "button" at the center of the
screen. In fact, another chunk was stuck in the gap, it was slightly too big
to fit.

Most likely valve seals, common on that vintage engine.

Quote:

In the bottom of the pan there were a few chunks, not much.

I cut open the oil filter, there were no chunks there.

That's because the chunks did not make it through the pump.

Quote:

There were two kinds of chunks in the pan - hard, black, glassy chunks and
black crumbly chunks. I think the crumbly chunks were cork or RTV from the
oil pan seal. I don't know what the hard, glassy chunks are.

Black crumbly valve stem seal. Hard glassy the plastic that is on the cam timing
gear. Both common failures. Removing the timing cover will verify.

Quote:

The chunks in the pump were of the hard, glassy variety. They are brittle,
perhaps 0.050-0.070" thick. There was a large chunk in the pan, same
thickness, oddly shaped, perhaps 0.250" square. What's wierd is it has some
curvature, like it is from a piece of a broken glass tube about 3/4 inch
diameter. These chunks can be broken fairly easily; they don't crumble but
they shear when you twist or press them or poke them with a dental pick.
There is no damage to the pump because the chunks are softer than the rotors.

The chunks are not pieces of piston rings, nor pieces of metal or actual
glass. On the large chunk, on the outer surface, under a magnifying glass
the surface has light scoring in the circumferential direction. The corners
of the edges look like they may have been sharp at one time, but had become
rounded. The corners of the chunks in the pump were sharper.

Evidently, the chain of events started when I accelerated with a nearly-cold
engine (its 50 degrees in Phoenix these days) and with a low oil level. Did
this make it easy to pick up chunks? Did it generate the chunks? Why didn't
it eat the chunks sooner? Either the chunks just now dropped into the pan
and got sucked up, or they've been there a while and just now got sucked up,
maybe because the hole in the screen just now opened wide enough, or the
chunks just now got small enough to fit throught the hole in the screen

No the chain of events started a long time ago, the plastic has been in the
process of coming apart slowly over time.

Quote:

I could get running again by replacing the pump drive shaft and the pick-up
tube and screen to get a screen having no holes, but this doesn't eimininate
the source of the chunks. Will there be more chunks?

Not only will there be more chucks, but the engine may not run due to a slipped
timing chain because the plastic teeth are missing on the cam gear.

Quote:

What kind of chunk is shaped like a piece of curved glass? Did it come from
under the valve covers? From behind the front cover (in the region of the
cam drive)? I can't imagine it came from the clinders, because these chunks
would not fit the clearance between cylinder and piston.

Are these chunks a coating of some sort, perhaps building up over time and
finally breaking loose?

They coat the cam gear for noise control.

Quote:

Nothing inside the surface of the oil pan
looks like this, nor does anything in the bottom of the block or cylinders.
Maybe they fell off the surface of the valve covers or some other surface. I
can't see inside those covers unless I remove the covers or get a boroscope.

You have the pan off, do it right and go the rest of the way.

Quote:

So, any tips?

Mike

Plastic timing gears, maybe?

Rob

#8

SWG wrote:

Quote:

I'd go with the valve seals. If they were rubber to start with. Especially
if the engine has overheated or ran hot for a while. Its happened to me 20
odd years ago.

It did run hot last year (fall 2003) when the radiator got plugged. I
suppose I can't avoid taking off the valve covers to see what's going on
in there.

Quote:

If it was an original 77 engine I'd agree some of the larger chunks could be
from the nylon cam gears that were used back then, but I've never seen
pieces from them small enough to get thru the pickup screen. They were
"natural" or opaque white in color.

Was the entire gear made of plastic? Was it a coating? The pieces
don't look like gear teeth or gear body, but I suppose that it's not
impossible.

The pickup screen itself is intact, as its outer attachment, but there
is a strip of sheet metal about an inch wide across the center that
obscures seeing the whole screen. When I look under that strip from the
side, it seems the center of the screen is open but covered by something
that looks like a button, and the screen under the button is open enough
for pieces about a tenth of an inch to get through. I think I need a
new pickup.

Quote:

Check the bearings front and rear for scoring. There probably won't be any
to speak of. Replace the valve seals. Clean or replace the pump. Its a good
time to switch to a high volume pump if you choose to replace it. They come
with the drive rod. (or did)

Do I remove the heads to replace the valve seals? It's been so long ago

when I rebuilt the engine that I forgot.

Is a high volume pump something to be found at, say, NAPA? Is it an
item I get from a high-performance shop?

Quote:

Wayne

It would be great to get a boroscope so I can look around inside the
front cover or under the valve covers. I'd really like some more
evidence what the source of chunks is before I start tearing things
apart. Do you suppose there are places to rent one?

Mike

#9

"Michael Bonnice" <mike.bonnice.no.spam (AT) pobox (DOT) com> wrote

Quote:

SWG wrote:

I'd go with the valve seals. If they were rubber to start with.
Especially
if the engine has overheated or ran hot for a while. Its happened to me
20
odd years ago.

It did run hot last year (fall 2003) when the radiator got plugged. I
suppose I can't avoid taking off the valve covers to see what's going on
in there.

If it was an original 77 engine I'd agree some of the larger chunks
could be
from the nylon cam gears that were used back then, but I've never seen
pieces from them small enough to get thru the pickup screen. They were
"natural" or opaque white in color.

Was the entire gear made of plastic? Was it a coating? The pieces
don't look like gear teeth or gear body, but I suppose that it's not
impossible.

It was just a coating over the teeth area.

Quote:

The pickup screen itself is intact, as its outer attachment, but there
is a strip of sheet metal about an inch wide across the center that
obscures seeing the whole screen. When I look under that strip from the
side, it seems the center of the screen is open but covered by something
that looks like a button, and the screen under the button is open enough
for pieces about a tenth of an inch to get through. I think I need a
new pickup.

Check the bearings front and rear for scoring. There probably won't be
any
to speak of. Replace the valve seals. Clean or replace the pump. Its a
good
time to switch to a high volume pump if you choose to replace it. They
come
with the drive rod. (or did)

Do I remove the heads to replace the valve seals? It's been so long ago
when I rebuilt the engine that I forgot.

Yes, but you don't have to. I think its easier to remove them.

Quote:

Is a high volume pump something to be found at, say, NAPA? Is it an
item I get from a high-performance shop?

NAPA should have them, as well as other parts places.

Quote:

Wayne

It would be great to get a boroscope so I can look around inside the
front cover or under the valve covers. I'd really like some more
evidence what the source of chunks is before I start tearing things
apart. Do you suppose there are places to rent one?

Valve cover gaskets aren't expensive. In fact, I've got a box of 25 in the
basement for Ford small blocks.

I doubt if I'd take off the front cover as once you look at the valve seals
you'll know thats where your chunks came from. I'd bet at least 4 of the 16
seals won't be inside the springs.

Wayne

Quote:

#10

Michael, In my opinion It's a good idea to rebuild at this point. It sounds
like your engine hasn't been rebuilt before, at least not properly that is,
if the cooling system was once clogged by debris from the block. The
"plastic" you describe in the oiling system could be from old style timing
gears and/or old valve stem seal debris. It's possible the chunks could have
been stuck in the oil screen when "rebuilt" last or somewhere in the block
even though now, you have a metal geared timing chain. If the pump froze at
the time you pulled over and you then drove it home slowly, it's most likely
you scored your cylinder walls and damaged your bearings. I don't think
you'll be happy if you just throw a new pump on and call it good, unless
you're very lucky. Even then, you'll have problemes with the engine soon.
Good luck and let us know what happens.