This bulletin refers to engine knocking or ticking at idle, with the noise usually more noticeable when the engine is warm. The probable cause is excessive clearance at the rocker shaft bridge which causes the rocker shaft to rotate and produce the noise. Affected vehicles includes 2008 Accord V6 with automatic transmission, 2008 Odyssey EX-L/Touring and 2009 Pilot 2DW and 4WD vehicles.
The corrective action involves loosening and re-torquing the rocker shaft bridge bolts.
- Start the engine and allow it to reach operating temperature.
- While the engine is idling, listen for a knock or tick, using a stethoscope. If the noise is evident at either cylinder head, proceed with this bulletin.
- Remove the cylinder head covers. Note: To ease cover removal, remove the power steering pump with its hoses connected. This allows access to the wire harness mounting bolts.
- Starting with the front cylinder head, loosen and then torque each rocker shaft bridge bolt in the sequence shown here. Torque bridge bolts 1 through 8 to 19 ft-lb. Torque bridge bolts 9 and 10 to 18 ft-lb.
Note: The bridge is designed to crush around the rocker shaft, so when torquing the bolts, it may initially feel like the bolt is stripped. This is normal. Continue torquing bolts until the appropriate torque valve is reached. Do not replace the bolt, bridge or the head. Do not over-torque the bolts, as they may break. The bridge bolts for VCM and V-TEC engines have the same torque values and tightening sequences.
- Repeat the process with the rear cylinder head.
- Check valve clearances and adjust if needed.
- Reinstall the cylinder head covers and power steering pump.
- Start the engine and verify that the noise is gone when the engine is at operating temperature.
