Fuel System - Ticking Noise From Rear Of Engine
TECHNICALBulletin No.: 09-06-01-004
Date: April 01, 2009
Subject:
Clicking/Ticking Sound/Noise Heard From Rear of Engine (Install Sound Isolation Cover Over High Pressure Fuel Pump)
Models:
2008-2009 Chevrolet Cobalt, Cobalt SS, HHR, HHR SS
2007-2009 Pontiac Solstice GXP
2007-2009 Saturn SKY Redline
2007-2009 Opel GT
2007-2009 Daewoo G2X
Equipped with 2.0L Engine (VIN X - RPO LNF)
Condition
Some customers may comment on a ticking sound from the rear of the engine. Upon investigation, the technician may find the sound coming from the high pressure fuel pump and/or the injectors.
Cause
The 2.0L turbo engine (VIN X - RPO LNF) uses a direct injection fuel system that operates at very high fuel pressures. A direct injection fuel system produces a rapid, clicking/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 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. These sounds are the results of a normal direct injection fuel system operating properly.
Correction
Install a sound isolation cover over the high pressure fuel pump following the procedure below. This will make the sound coming from the high pressure fuel pump less noticeable, but it will not completely eliminate it.
Important
DO NOT attempt to replace any parts for this kind of clicking or ticking concern.
1. Verify the noise is coming from the high pressure fuel pump.
2. Remove the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement in SI.
3. Disconnect the engine wiring harness electrical connector from the high pressure fuel pump.
4. Remove the engine wiring harness from the high pressure fuel pump cover bracket.
5. Remove the high pressure fuel pump cover bolts (1).
6. Remove the high pressure fuel pump cover bracket.
7. Remove the old design cover and install the new high pressure fuel pump insulator, GM P/N 12628069.
8. Position the high pressure fuel pump cover bracket. Install the high pressure fuel pump cover bolts.
Tighten
Tighten the bolts to 10 Nm (89 lb in).
9. Connect the engine wiring harness electrical connector to the high pressure fuel pump.
10. Attach the engine wiring harness to the fuel pump cover bracket using a zip tie.
11. Install the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement in SI.
Parts Information
Warranty Information
For vehicles repaired under warranty, use the table above.
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