Dodge 2001 Ram 1500 Owner's Manual page 1242

BR/BE
DISTRIBUTOR BUSHING (Continued)
Fig. 35 Burnishing Distributor Driveshaft Bushing
1 - SPECIAL TOOL C-3053
2 - BUSHING
(4) Install the intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE
INSTALLATION).
(5) Install the distributor (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/DISTRIBUTOR
INSTALLATION).
HYDRAULIC LIFTERS (CAM IN
BLOCK)
DIAGNOSIS AND TESTING—HYDRAULIC
TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, check the oil pressure. If vehicle
has no oil pressure gauge, install a reliable gauge at
the pressure sending-unit. The pressure should be
between 207-552 kPa (30-80 psi) at 3,000 RPM.
Check the oil level after the engine reaches normal
operating temperature. Allow 5 minutes to stabilize
oil level, check dipstick. The oil level in the pan
should never be above the FULL mark or below the
ADD OIL mark on dipstick. Either of these two con-
ditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible
for the connecting rods to dip into the oil. With the
engine running, this condition could create foam in
the oil pan. Foam in oil pan would be fed to the
hydraulic tappets by the oil pump causing them to
lose length and allow valves to seat noisily.
LOW
When air is fed to the tappets, they lose length,
which allows valves to seat noisily. Any leaks on
intake side of oil pump through which air can be
drawn will create the same tappet action. Check the
lubrication system from the intake strainer to the
pump cover, including the relief valve retainer cap.
When tappet noise is due to aeration, it may be
intermittent or constant, and usually more than one
tappet will be noisy. When oil level and leaks have
been corrected, operate the engine at fast idle. Run
engine for a sufficient time to allow all of the air
inside the tappets to be bled out.
TAPPET NOISE DIAGNOSIS
MANIFOLD -
engine at idle with cylinder head covers removed.
noisy tappet. The noisy tappet will cause the affected
-
spring and/or rocker arm to vibrate or feel rough in
operation.
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy tappets. If such is
the case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in the
tappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger, or by the
plunger partially sticking in the tappet body cylinder.
The tappet should be replaced. A heavy click is
caused by a tappet check valve not seating, or by for-
eign particles wedged between the plunger and the
tappet body. This will cause the plunger to stick in
the down position. This heavy click will be accompa-
nied by excessive clearance between the valve stem
and rocker arm as valve closes. In either case, tappet
assembly should be removed for inspection and clean-
ing.
like a light tappet noise during normal operation.
Care must be taken to ensure that tappets are mak-
ing the noise. If more than one tappet seems to be
noisy, it's probably not the tappets.
LEAK-DOWN TEST
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 36).
pet tester away from the ram of the Universal Leak-
Down Tester.
Low oil level may allow oil pump to take in air.
(1) To determine source of tappet noise, operate
(2) Feel each valve spring or rocker arm to detect
(3) Valve tappet noise ranges from light noise to a
(4) The valve train generates a noise very much
After cleaning and inspection, test each tappet for
Swing the weighted arm of the hydraulic valve tap-
ENGINE 5.2L 9 - 95