Ignition - Engine Spark Knock at Idle

File In Section: 6E - Engine Fuel & Emission

Bulletin No.: 77-65-22

Date: October, 1997

Subject:
Engine Spark Knock at Idle
(Flash with New Calibration)

Models:
1995-96 Chevrolet Camaro
1995-96 Pontiac Firebird
with 3800 Series II Engine (VIN K - RPO L36) and Automatic Transmission

Condition

Some owners may comment about a spark knock noise when the engine is idling with the transmission selector placed in drive and brakes applied. The condition may be most noticeable when ambient temperature is above 96°F (35°C).

Cause

Current Powertrain Control Module (PCM) calibration may adjust the engine spark advance too high during these temperatures and load conditions.

Correction

Reflash the PCM with the new calibration. The new calibrations are available beginning with 1997 CD Disc 18 from GM Service Technology Group.

Important:
Do not attempt to order the calibrations from GMSPO. The calibrations are programmed into the vehicle's PCM via a Tech line Tool Device.





Parts Information

Warranty Information





For vehicles repaired under warranty, use the table.