AIR CLEANER MODIFICATION SNOW IMPACTED (SER. PROC.)

SUBJECT: AIR CLEANER MODIFICATION/SNOW IMPACTED

VEHICLES AFFECTED: 1986-1988 C6,C7,P6,B6 W/8.2L (VIN F,G) AND 3208 CATERPILLAR (VIN Y)

The subject vehicles were manufactured with an engine air inlet scoop mounted behind the grille and an air inlet tube which connects it to the engine air cleaner. During certain operating conditions, snow may enter the scoop and be deposited in the inlet tube or air cleaner element. If enough snow enters the intake system, the air cleaner element will become restricted and engine power and performance may be reduced.

Under certain circumstances, snow impacted around the air cleaner may melt and soak the air cleaner element. If enough water is present, it may pass through the element and enter the engine. if the operator attempts to start the engine when these conditions occur, it may result in engine hydrostatic lock.

To address this condition , the following procedure may be implemented concerning the intake system.

SERVICE PROCEDURE

1. Remove the air inlet hose/tube (#6) between the radiator air scoop and the air cleaner canister. (See figure #1)

2. Remove eight bolts from the air cleaner canister and remove the canister (#4).

3. Drill three 1/4" diameter holes in the unfiltered air side of air cleaner canister base. (See figure #2)

a. Drill the holes at the lowest point of the air cleaner canister. The first hole should be opposite from air inlet tube.

Drill the two remaining holes 1/2" away from the first hole, one to the right and one to the left.

NOTICE: All drilling should be done with the air cleaner off the engine, to prevent metal shavings from entering air inlet system.

4. After drilling has been performed, clean and install the air cleaner assembly.

NOTICE: In applications where the vehicle is used to plow snow, leave the air inlet hose off (#6) during snow removal usage. Reinstall air inlet hose for warm weather operation.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.