NEW SPARK PLUGS RELEASED REDUCES PLUG BOOT STICKING

Subject: NEW SPARK PLUGS

Model and Year: 1992 LUMINA (APV) WITH 3800 TPI ENGINE

This bulletin is to inform technicians of a change in the spark plugs for vehicles with the 3800 TPI (Code L) engine.

In February of 1992, a new spark plug was released in production for the engines listed above to improve the spark plug to spark plug boot connection.

Exposure to underhood temperatures over period of time has the tendency to increase the bond between the boot and the spark plug ceramic. In the past, different lubricants have been used in the spark plug boots with varying success. This new spark plug was released to reduce this bonding condition and to improve the dielectric strength between the plug and the boot.

This new spark plug can be visually identified by its smooth ceramic surface, the ridges have been removed (see figure 1). These new spark plugs have an anti-stick material coating baked onto the spark plug's outer ceramic surface. This coating is clear with a slightly waxy feel. To further help identify the new spark plug, the type number has been changed to 41-600 from R45LTS6.

To maintain the reduced bonding characteristics, the Service Replacement Spark Plug 41-600 must be used, Service Package Number 5614253. The 41-600 Spark Plug is the recommended plug to use in all 1992 models listed above.

PARTS INFORMATION:

Parts are expected to be available on April 13, 1992. In case of limited inventory, parts will be placed on 400 control to waive VIP surcharges. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation at dealer's expense and all other order types will be placed on backorder until the 400 control is removed.

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.