Chirp Noise From Transmission Bell Housing Possble PCV Restriction - keywords air assembly cast casting chirping cleaner duct engine flash intake main oil pan rear resonator seal squeal whine whistle

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

On rare occasions, a chirp, squeak, or whistle noise may be heard from inside of the transmission bell housing. This noise may be coming from the rear main oil seal of the engine due to excessive vacuum in the crankcase.

If this concern is experienced, temporarily remove the oil fill cap and re-evaluate the noise. If the noise is no longer present, inspect the PCV fresh air port shown below for a restriction. Remove the restriction or replace the air cleaner outlet duct assembly as necessary and re-evaluate the concern.

1) PCV Fresh Air Port

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.