Engine - Whistling Noise

SOURCE: Kia PitStop

TITLE: Whistle from Engine

APPLIES TO: All 3.5L Sigma Engines

SERVICE TIP:

Under certain conditions a whistling noise similar to a vacuum leak can occur in 3.5 L Sigma engines between base idle and 1500 RPM. KMA field staff has verified that an aftermarket oil filter can cause this concern. The noise may be the result of changed oil pressure/flow interaction between filter and pressure relief valve in the engine oil pump. If the concern vehicle you are diagnosing has an aftermarket oil filter installed a visual inspection as well as a check of intake manifold vacuum and short fuel trim readings should be made first to insure there is no vacuum leak causing a concern. Once that is confirmed, replace the aftermarket filter with an original Kia replacement filter and verify that concern is resolved.