W350 1 Ton Pickup 4WD V8-360 5.9L VIN 1 4-bbl (1988)
Engine Oil Dip Stick - Dip Stick Tube: All Technical Service Bulletins
Engine - Lower End Tapping Noise
NO: 09-04-94
GROUP: Engine
DATE: Apr. 8, 1994
SUBJECT:
5.9L Lower Engine Tapping Noise
MODELS:
1989 - 1990
(AB)
Ram Van/Wagon
1988
(B)
Ram Van/Wagon
1989 - 1990
(AD)
Ram Pickup/Ram Cab & Chassis
1988
(D)
Ram Pickup/Ram Cab & Chassis
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 5.9L ENGINE THAT WERE BUILT IN 1990 OR PRIOR TO 1990.
SYMPTOM/CONDITION:
A lower engine tapping sound may occur following a service repair to a 5.9L engine. This engine repair would have involved the replacement of one of
the following components: a short block, a connecting rod, or a connecting rod bolt. The tapping sound will occur when the original oil pan is reused
during this service repair.
DISCUSSION:
A 1990 mid-model year change was made to the connecting rod bolt. The end of the bolt was increased in length by 10 mm. A tapping sound is caused
by the end of the connecting rod bolt contacting the oil pan dipstick guide. Service replacement oil pans and late 1990 production 5.9L engine oil pans
have the oil dipstick guide shifted forward toward the front of the oil pan. This allows for the necessary bolt-to-oil pan clearance. Older oil pans may
require the following procedure to be performed (Refer to Item A in Figure 1).
DIAGNOSIS:
The origin of the tapping-like noise will come from the right side of the oil pan. The noise can be further localized to the front, top corner area of the oil
pan. The technician will be able to localize this tapping noise with his ear and his hand. The technician may also notice a noise and interference as he
rotates the engine by hand.
REPAIR PROCEDURE:
This bulletin involves the modification of the oil pan dipstick guide, which is located inside the engine oil pan.
NOTE:
THE TECHNICIAN SHOULD PERFORM THIS PROCEDURE DURING HIS ENGINE ASSEMBLY PROCESS AND WHILE THE OIL PAN IS
STILL REMOVED FROM THE ENGINE.
1).
With the oil pan already removed from the engine, locate the oil pan dipstick guide.
2).
If the engine tapping noise had been present, there should be evidence on the dipstick guide of contact by the end of the connecting rod bolt.
