Engine - Objectionable Vibration
BULLETIN NO.: 94-T-16ISSUE DATE: May, 1994
GROUP/SEQ. NO.: Chassis-01
CORPORATION NO.: 486105
SUBJECT:
Objectionable Engine Vibration at Idle (Replace Engine Mount Assembly)
MODELS AFFECTED:
1992-1993 Saturns
CONDITION:
Some customers may comment about objectionable engine vibration during idle. Vehicles equipped with automatic transaxles may also exhibit a harsh 2-3 upshift. This condition may be more noticeable when the engine is cold.
CAUSE:
Condition may be caused by change in material properties in rubber isolation cushion of the engine mount assembly.
CORRECTION:
Perform the following procedure to check the engine mount and, if necessary, replace the engine mount assembly according to procedure in this bulletin.
PROCEDURE:
1. Using two 150 mm (6 in.) scales or a 150 mm (6 in.) scale and a suitable straight edge, measure engine mount assembly as shown.
IMPORTANT:
To ensure accurate measurement, hold the straight edge flat against the machined, flat top surface of the front cover. Make sure the vertical scale rests on flat surface of the engine mount assembly, not on the fold-over tang found on some engine mount assemblies.
2. If the measurement is equal to or less than 39 mm (1-17/32 in.), proceed to "Engine Mount Assembly Replacement" procedure in this bulletin and replace the engine mount assembly. If the measurement is greater than 39 mm (1-17/32 in.), refer to "Technical Information Bulletin 91-T-36B" (Corporation No. 180106R) to correct condition.
Engine Mount Assembly Replacement
1. Remove the two engine mount-to-midrail bracket nuts and discard.
2. Place a floor jack under the engine oil pan (use a block of wood between the oil pan and the jack). Raise the powertrain just enough to unload the engine mount assembly. (Engine is raised enough when there is clearance between the engine mount assembly and midrail bracket.)
NOTICE:
If the engine mount front cover stud turns or comes out during nut removal, the stud must be fully installed prior to installing the engine mount assembly and/or nut. Damage to the front cover may occur if the stud is driven with the nut and does not sufficiently engage the front cover threads. (Refer to "Engine Mount Front Cover Stud(s)" in the "Powertrain Mounts" section of the "Chassis Service Manual.")
3. Remove the three engine mount-to-front cover nuts and discard.
4. Remove engine mount assembly.
5. Position new engine mount assembly (P/N 21012194) to the front cover and install new engine mount-to-front cover nuts.
Torque: 50 N-m (37 ft.lbs.)
NOTICE:
When lowering the powertrain, it will be necessary to guide the engine mount assembly over the midrail bracket studs to prevent damage to the stud threads.
6. Lower the powertrain completely.
7. Install new engine mount-to-midrail bracket nuts.
Torque: 50 N-m (37 ft.lbs.)
CAUTION:
MAKE SURE VEHICLE IS PROPERLY SUPPORTED AND SQUARELY POSITIONED ON HOIST. TO HELP AVOID PERSONAL INJURY, PROVIDE ADDITIONAL SUPPORT TO THE OPPOSITE END OF THE VEHICLE THAT COMPONENTS WILL BE REMOVED FROM.
8. Raise vehicle on a hoist.
9. Loosen the two engine strut bracket-to-cradle fasteners to remove any fore/aft preload from the engine strut.
10. Tighten the two engine strut bracket-to-cradle fasteners.
Torque: 50 N-m (37 ft.lbs.)
11. Lower vehicle from hoist.
PARTS REQUIREMENTS:
21012194 Mount Asm-Engine
21006320 Engine Mount Nuts
CLAIM INFORMATION:
To receive credit for this repair, submit a claim through the Saturn Dealer System as follows: (see illustration)