Whistle or Whine Noise From Oil Pressure Relief Valve - keywords engine replace replacement

This PI was superceded to include some 2006 production engines. Please discard PIP4421A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Some customers may notice a whistle or whine noise at idle. Upon inspection, this noise will be isolated to the AFM (Active Fuel Management) relief valve in the oil pan.

This noise should not occur unless the oil pan contains an AFM relief valve. Currently, all 2005-2006 GTO replacement engines, and some 2006 production engines, contain an AFM relief valve. However, 2005 production engines did not contain one. As a result, this noise should not be experienced on a 2005 GTO unless the engine has been replaced with an engine that contains an AFM relief valve. This AFM relief valve is not needed for the 2005-2006 GTO because it is not equipped with AFM.

If this noise is experienced, remove the AFM relief valve, insert plug part number 11561583 (M14 x 1.5) in the hole, torque it to 21 lb/ft (28 Nm), and re-evaluate the noise.

When replacing an engine that does not have an AFM relief valve, this potential noise can be prevented by installing the old oil pan onto the new engine.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.