We have low oil pres in '96 Discovery. Found
broken cam follower in oil pan. Where is oil
pump? Catalog shows gear driven pump
near timing chain cover??? Oil sump intake
leads into block midengine very far from
pump location. Any suggestions? Please help!

 

NAS Oil pump is in the front cover. What do you mean by cam follower ? You got a push rod V-8 right ?

 

Yes, pushrod V8. The metal rod found in
oil sump is a short section of solid metal
rod (no bore for oil passage) and has
a "ball" at one end. Looks like a pushrod
but looks more like it had a tappet
on end. Thats why described as "cam
follower" (made up word.) Mysterious
because the parts catalog describes
the oil pump for the 4.0L V8 as in
the timing cover, the front of the
engine. It is integral unlike the
gear style pump of the 4.2 L V8 which
is removeable. Additionally, when
you trace the oil gallery from the
sump intake, it leads upward mid
engine from the sump to the rockers.
We haven't removed the rocker
covers yet for obvious reasons.
We were wondering if the oil
pump is driven by an extra cam
lobe on the cam (I know the cam
is not located in the rocker area
but that is where the oil pipe leads.
We thought that the broken "stick"
of solid metal rod may have been
part of a pump drive that rides
a cam lobe same as lever driven
fuel pumps on some other older
vehicles.

Removing the front located oil
pump is quite a bit of hassle. And
they say oil pumps never fail. Wanted
to find out if we were barking up the
wrong tree.

 

Pete, the oil pump is directly driven by the crank in the front cover. Low oil pressure is most likely from a spun bearing or slipped cam bushing.

 

Bait: Thanks very much. I'll tell the mechanic!

 

Mechanic removed bank A rocker arm cover and discovered other
half of broken push rod, lifter out of place and cracked rocker arm
shaft. Shaft had literally split between cyl 1 rockers. I'll make note
when repair complete. PMV

 

Rocker arm replaced with part from LandRoverParts.com.
Broken pushrod replaced and tappet put into its
proper place. Reassembled everything, drained and
changed oil and filter. Vehicle runs perfectly well
with no DTC's. All Clear. Revs smoothly to 5K rpm.
No symptoms of cylinder damage... Thanks!

 

Any idea what may have caused it?
And thanks for the follow up it is something
that I would have missed.

 

Not really, just speculation. The bank a rocker arm
gallery looked like it had run with low oil and got hot.
Entire surface had that baked on oil look. Mabe rocker
arm frozen due to lack of oil flow due to low oil in crankcase.
If rocker frozen then push rod could be compressed between
rising tappet and frozen arm. The pushing of rod on frozen
rocker could also break the shaft at the mounting place.

Mechanic said possibly there was a flaw in the rocker arm
shaft casting. He noted two flat spots in the break which looked
like an existing weak spot. Maybe a manufacturing defect. Not
sure however.