I have a 2003 300b, normally aspirated, just rolled over 190k miles. When the engine/trans are cold, under light or heavy acceleration there is a whine, something like a supercharger whine or bad P/S pump, from the front of the car. The harder the acceleration the louder the whine. The whine pitch goes up as engine speed rises. The whine does not occur at idle or when the trans is in park or neutral, even when engine is revved in park. During the first few minutes of cold operation, if the car is moving and I drop into neutral and then rev the engine, there is no whine. If I move back into drive the whine immediately returns when throttle is applied. After the engine/trans is warmed up, the whine can only be heard under heavy acceleration. When warm, during cruising or light/medium throttle there is no whine. Whine noise does not change when steering wheel is turned. "Cold" = room temperature, not polar vortex. I noticed the whine a few weeks ago and it does not seem to be getting louder, or longer in duration.
Trans fluid was changed 7k miles ago and is full. P/S fluid was changed 7k miles ago and is full. Both are Mercon V. Alternator was replaced new about 40k miles ago. Serp belt + tensioner + idler pulley were replaced 45k miles ago. Timing chain tensioner and guides replaced about 50k miles ago. I put a borescope down inside the front cover and timing chain guides looked to be intact, no broken off plastic, etc.
Any ideas where to start looking for the source of the whine?
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Originally Posted by Peace2Peep
