2019 GMC Truck Acadia AWD V6-3.6L Technical Service Bulletin # 07-06-04-025H Date: 120727

Fuel System - Clicking/Ticking Noises On Cold Start Up
INFORMATION
Bulletin No.: 07-06-04-025H
Date: July 27, 2012
Subject: Information on Clicking/Ticking Sound/Noise Heard During Cold Start
Models:
2009-2013 Buick Enclave
2010-2013 Buick LaCrosse
2008-2011 Cadillac STS
2008-2013 Cadillac CTS
2010-2013 Cadillac SRX
2013 Cadillac ATS, XTS
2009-2013 Chevrolet Traverse
2010-2013 Chevrolet Camaro, Equinox
2012-2013 Chevrolet Impala
2009-2013 GMC Acadia
2010-2013 GMC Terrain
2009-2010 Saturn OUTLOOK
Equipped with 3.0L or 3.6L VVT Direct Injection V6 Engine (VINs G, D, 5, V, Y, 3 - RPOs LF1, LFW, LLT, LFX)
Supercede:
This bulletin is being revised to add the 2013 model year and the Cadillac ATS, XTS models. Please discard Corporate Bulletin Number
07-06-04-025G (Section 06 - Engine/Propulsion System).
The 3.0L and 3.6L SIDI engines use 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 (located on the rear of the left 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 is the fuel injectors pulsing on and off under higher fuel pressures. This sound is a normal characteristic of Direct Injection Fuel high
pressure fuel system.
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
2019 GMC Truck Acadia AWD V6-3.6L Page 26
concerns with the engine or the vehicle. You may wish to give the customer a copy of this bulletin.
Disclaimer