Whistle Noise From Throttle Body Area At Or Near Idle - keywords engine gasket LE5 intake manifols orifice plate

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

Some customers may report a whistle noise that is heard at or near idle. Upon inspection, the technician should be able to isolate the noise to the throttle body area of the engine. If the noise is compared with others, it may also be determined that this is a noise characteristic of the engine.

If the SI diagnostics do not isolate the root cause of this noise, perform the following steps to improve this noise characteristic:

1. Follow the Intake Manifold Replacement Procedure in SI to remove the intake manifold.
2. Remove the PCV orifice plate that is between the #2 and #3 intake manifold runners.
3. Plug the PCV orifice by placing a small amount of epoxy on both sides of the PCV orifice plate as shown below in Step 4.
4. Use a #51 (.067" / 1.7 mm) drill bit to drill a new orifice in the location shown below.



5. Install the PCV Orifice Plate as shown below.



6. Follow the Intake Manifold Replacement Procedure in SI to install the intake manifold.

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.