Fuel - Clicking/Ticking Noise From Rear Of Engine
TECHNICALBulletin No.: 11-06-01-002A
Date: December 02, 2011
Subject: Clicking, Ticking Noise from Rear of Engine (Install Sound Insulator Between High Pressure Fuel Pump and Fuel Pipe Connection)
Models:
2010-2011 Buick LaCrosse, Regal
2010-2011 Chevrolet Equinox
2010-2011 GMC Terrain
Equipped with 2.4L Engine RPO LAF
Attention:
Certain 2011 vehicles are involved in Campaign #11195B and may exhibit a cold start rattle. Refer to Required Field Actions in the Global Warranty System for involved vehicles. If the vehicle is involved in #11195B then repair the vehicle for that first. If the customer is still not satisfied with the continual ticking noise that is referenced in this PI, then install the insulator as outlined in the procedure below and write the
repair up as "Customer Satisfaction."
Supercede:
This bulletin is being revised to add an Attention statement. Please discard Corporate Bulletin Number 11-06-01-002 (Section 06 - Engine/Propulsion System).
Condition
Some customers may comment on a clicking, ticking noise coming from the rear of the engine.
Upon investigation, the technician may find the sound coming from the high pressure fuel pump to fuel pipe connection area.
Cause
The 2.4L engine uses a direct injection fuel system that operates in a range of very high fuel pressures. A direct injection fuel system produces a rapid, clicking, ticking noise that can be heard coming 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 high pressure 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 slower rate of approximately one tick per second during idle. There are additional clicking noises that will come from the fuel injectors pulsing on and off under the higher fuel pressures.
Correction
Install a sound insulator between the high pressure fuel pump and fuel pipe connection, following the procedure below. This will make the sound coming from the high pressure fuel pump area less noticeable, but it will not completely eliminate it.
Important
DO NOT replace any parts for this kind of clicking or ticking noise as this is a normal operating characteristic of the direct injection high pressure fuel system.
1. Verify that the noise is coming from the high pressure fuel pump to fuel pipe connection area.
• If the noise is coming from the high pressure fuel pump to fuel pipe connection area, proceed to Step 2.
2. Turn OFF the ignition. Remove the engine oil cap.
3. Remove the intake manifold cover (2).
4. Disconnect the electrical connector of the high pressure fuel pump.
5. Remove the two engine wiring harness retaining clamps (1) that are seated in the high pressure fuel pump cover.
6. Remove the three high pressure fuel pump cover fasteners (1).
1. Remove the high pressure fuel pump cover (2).
2. Remove the high pressure fuel pump sound insulator (3).
7. Position the sound insulator underneath the high pressure fuel pump and slide the grooved opening around the high pressure fuel pump to fuel pipe connector as shown.
8. Properly position the sound insulator (2) as shown. It should be snug against the engine intake manifold and the upper high pressure fuel pump sound insulator (1), once that is installed.
9. Install the high pressure fuel pump sound insulator.
10. Install the high pressure fuel pump cover (2).
Install the three high pressure fuel pump cover fasteners (1).
Tighten
Tighten the fasteners to 10 Nm (89 lb in).
11. Connect the electrical connector of the high pressure fuel pump.
12. Secure the two engine wiring harness retaining clamps (1) into the high pressure fuel pump cover.
13. Install the intake manifold cover.
14. Install the engine oil cap.
Parts Information
Warranty Information
For vehicles repaired under warranty, use the table.
Disclaimer