First post in forever on here. Motor has around 90K miles Transmission has around 110K miles I'm getting a strange whistling for the first 20 minutes or so on a cold motor. It's not rev dependent or boost dependent. Doesnt matter if the clutch is in or out. The only thing I can determine is that it happens when I'm moving more than 10mph, below that speed the whistling goes away. Steady whistling, doesnt change pitch at all, just goes for the first 20 minutes until something warms up. Only goes away when slowing to a complete stop and again doesnt matter if the car is engine braking or coasting to a stop in neutral. I dont recall noticing it before my most recent oil and spark plug change a few weeks back but neither of those should have made a difference. Anybody have an idea? This is kinda driving me insane since most of my driving is shorter trips.
Not engine/driveline related since it doesn't change with rpms. It's not cold enough to be crossbars. I'd check the plastic undercarriage covers for loose or missing attachment hardware - loose tray could possible make a whistle when air moves over it.
That was my guess based on the speed dependency but odd that it goes away once I've been driving for a while. I did detail the car before doing the oil change and spark plugs so something might have gotten knocked around.