Fuel System - Clicking/Ticking Sound/Noise On Cold Start
INFORMATIONBulletin No.: 06-06-93-001G
Date: April 04, 2011
Subject: Clicking/Ticking Sound/Noise Heard During Cold Start - Sound/Noise Decreases, But Continues As Engine Warms - Normal Operation of High Pressure Fuel Pump and Injectors
Models:
2008-2009 Chevrolet Cobalt SS, HHR SS
2007-2009 Pontiac Solstice
2007-2009 Saturn SKY
2007-2009 Opel GT
2007-2008 Daewoo G2X
Equipped with 2.0L Turbocharged Engine RPO LNF
Supercede:
This bulletin is being revised to remove the 2010 Chevrolet Equinox, GMC Terrain and the 2.4L engine RPO LAF. Please discard Corporate Bulletin Number 06-06-93-001F (Section 06 - Engine/Propulsion System).
The 2.0L turbocharged engine uses a direct injection fuel system that operates at very high fuel pressures. A direct injection fuel system produces a rapid, clicking and ticking sound that can be heard from the engine compartment. The sound is more evident when outside around the vehicle or when the hood is open. The sound is more noticeable during idle, and is more frequent during a cold start but lessens once the engine is warm. The rapid ticking noise on cold start up is the fuel pump, which is located on the rear of the cylinder head building up high fuel pressure. When the engine warm-up is completed, the high pressure fuel pump will continue to tick at a lower rate of approximately one tick per second during idle. The clicking sound are the fuel injectors pulsing on and off under higher fuel pressures. These sounds are the results of a normal direct injection fuel system operating properly.
DO NOT attempt to repair or replace any parts for this kind of clicking or ticking concern. The clicking or ticking sound is not indicative of any concerns with the engine or the vehicle.
You may wish to give the customer a copy of this bulletin.
Disclaimer