For 1990-2009 cars

# Noise From rear Of Vehicle During Cold Start - Potential Noise Characteristic - keywords BQMI

Subject: | Noise From Rear of Vehicle During Cold Start

Models: | 2004-2008 Chevrolet Aveo

| 2006-2008 Chevrolet Cobalt, HHR

| 2007-2008 Pontiac G5

| 2005-2006 Pontiac Pursuit (Canada Only)

| 2005-2008 Pontiac Wave (Canada Only)

| 2006-2007 Saturn ION

This PI was superseded to update models. Please discard PIC4317C.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

### Condition/Concern:

Shortly after cold starting the engine, 3-5 brief knock noises may be heard from the rear of vehicle that sounds like someone tapping on the rear window or quarter panel. This may be the result of the EVAP vent valve going through a normal diagnostic cleaning cycle.

### Recommendation/Instructions:

If this concern is experienced and the noise is isolated to the EVAP vent valve, inspect the vent valve pipe to ensure that it is routed properly and not grounding out. If the pipe is routed properly, this noise should be considered a normal characteristic and no repairs should be performed.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.