1. START ENGINE, RUN ENGINE APPROXIMATELY
5 MINUTES AT NORMAL IDLE.
Accelerate engine several times,
watch for excessive blue-gray smoke at the tail pipe.
Repeat above procedure several times. Should blue-gray
smoke continue to appear at the tail pipe this will indicate
oil is getting into the combustion chamber through the
vacuum booster pump, vacuum type breather, past the valves
or various other reasons.
2. AT THIS POINT A PROCESS OF ELIMINATION
SHOULD BE STARTED.
Start with the vacuum booster pump
(when used). A porous or damaged booster pump diaphragm
will allow oil to be pulled into the intake manifold through
the vacuum line running from the pump to the manifold.
Disconnect vacuum line at the pump and manifold, check
the connections and line for an oil deposit. Should oil
be found in the line, the pump must be replaced. After
replacing pump start engine and run at a fast idle for
20 to 30 minutes, accelerate the engine several times
during this period. If excessive engine smoking ceases,
you have licked the problem. CAUTION: Should the blue-gray
smoke continue after the pump is replaced the above procedure
should be repeated as new or rebuilt pumps are occasionally
found to be faulty.
3. VACUUM OPERATED CRANKCASE BREATHER.
This type breather system is standard
equipment on many engines. We have had various types of
installations and control valves in use. All types control
the amount of air drawn through the crankcase by use of
a control valve located between the intake manifold and
the crankcase or the valve chamber cover, and is connected
to a vacuum line. If the control valve becomes worn or
stuck in the open position the engine will consume large
quantities of oil. To check, disconnect the vacuum line
at the control valve. Remove the valve. If oil is found
in the valve this indicates oil is being pulled into the
combustion chamber. Replace the valve. Do not take a chance
on the old valve. After replacing the control valve, start
the engine. Repeat the smoke test as outlined in Step
4. CHECKING VALVE CHAMBER VENTILATING
Some vehicles are equipped with
a tube from the valve chamber cover to the air cleaner
which ventilates the valve chamber. In some cases the
air cleaner will pull oil through the ventilating tube
during periods of high air flow. Excessive oil and oil
vapors in the valve chamber will also add to the problem.
TO CHECK: Disconnect the ventilating tube and inspect
for an oil deposit in the tube. When oil is found, the
correction of this condition may require a longer ventilating
tube and relocation of the ventilating tube connection
on the air cleaner, and proper servicing of the valve
5. OIL LOSS THROUGH VALVE GUIDES.
There are various methods used to
lubricate the rocker arm shafts on 0. H.V. engines. For
this reason it is important to know the methods used so
the oil flow can be shut off, while a smoke test is made.
(A) External tube running from
the oil galley up to the rocker arm shaft. Disconnect
the tube and plug the line is all that is required to
shut off the oil to make a smoke test.
On V-8 engines three methods are
used to shut off the oil.
(B) One is to bring the oil up
through a drilled passage in the shaft bracket. To shut
off the oil flow in this system loosen the bracket and
slip a shim under the bracket restricting the oil passage.
(C) Another method is to use a
drilled hold down bolt in one of the shaft brackets, which
allows the oil to pass up through the bolt to the shaft.
To restrict the flow of oil in this system, remove the
drilled hold down bolt and replace with a solid bolt while
smoke test is made.
(D) Another method is use of undercut
hold down bolt. The center section being smaller than
the drilled hole in the shaft bracket which allows the
oil to flow to rocker arm shaft. To restrict the flow
of oil the undercut bolt can be replaced with a solid
bolt while the smoke test is being made.
(E) Canoe type rocker systems are
lubricated from the valve lifter through hollow push rods.
Clips are available from your jobber to stop oil from
After restricting the oil flow
as listed in A-B-C-D & E make a smoke test as outlined
in Step Two. If excessive smoke ceases it will be necessary
to make corrections. Hastings valve seals are available
from your Hastings jobber to correct this problem.
6. FURTHER CHECKS-
(A) On some V-8 engines the intake
manifold serves as the tappet chamber cover. A defective
gasket at this point will allow vacuum to draw oil from
the tappet chamber-replace gasket-carefully torque head
and manifold bolts.
(B) High oil level or high oil
pressure will flood the cylinders with excessive oil,
either or both must be corrected.
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