Grand AM L4-144 2.4L DOHC VIN T SFI (1997)
Spark Plug: Technical Service Bulletins
Ignition - Revised Spark Plug Gap
File In Section: 6E - Engine Fuel & Emission
Bulletin No.: 77-65-11A
Date: May, 1997
INFORMATION
Subject:
Production Spark Plug Gap Change
Models:
1997 Buick Skylark
1997 Chevrolet Cavalier, Malibu
1997 Oldsmobile Achieva
1997 Pontiac Sunfire, Grand Am
with 2.4L Engine (VIN T - RPO LD9)
This bulletin is being revised to add Chevrolet Malibu to models. Please discard Corporate Bulletin Number 77-65-11 (Section 6E - Engine Fuel &
Emission).
A change in spark plug gap has been made to reduce spark plug fouling during repeated low speed operation of these vehicles at assembly plants, rail
heads and dealer/retailer unloading points. The electrode gap of the production spark plugs has been reduced from 1.52 mm (0.060 in) to 1.27 mm
(0.050 in).
If a spark plug is removed to perform a service procedure and the gap is found to be 1.52 mm (0.060 in) and the spark plugs are functioning normally, do
not change the spark plugs.
Original equipment spark plugs will have the production part number imprinted on the ceramic insulator. The 1.52 mm (0.060 in) electrode gap spark
plug will have a production part number of 25164044 and the 1.27 mm (0.050 in) electrode gap spark plug will have a production part number of
25312636. The service spark plug part number for all 1997 LD9 engines is 25164048 with an electrode gap of 1.27 mm (0.050 in).
Important:
Do not mix spark plugs with different electrode gaps on the same engine. If it becomes necessary to change a spark plug in any of these vehicles
equipped with spark plugs that have a 1.52 mm (0.060 in) gap, replace all four spark plugs with GM Part Number 25164048 with the electrode gap
set at 1.27 mm (0.050 in).
