Bugeye - whirring noise when engine not running

[newguybugeye]

Hey guys... just got my car back from the shop to get the valve cover gaskets replaced, which is all fine and dandy, but it's started to make this weird whirring noise, almost like a belt or something that's still going once the engine has stopped.

I thought something might still be getting power so I disconnected the battery, but the noise doesn't stop. It's intermittent, and rises and falls.

It went on (sporadically) for about an hour before stopping. I'm guessing something has got residual charge and is still running until it bleeds off?

Anyway... I have a short video of the noise it's making, and the general area it's coming from. Was hoping you guys could help me as I'm really not that knowledgable about cars.

Thanks in advance!

[Rambo]

it's probably the passive cooling system for the turbocharger. Subaru basically uses a heat pump to recirculate coolant through the turbo, even after the engine is shut off. It's actually quite ingenious in that it doesn't require any external pump to function, it just uses the hot coolant fluid expansion to create a siphon which in turn draws cooler fluid through the turbo until the turbo cools.

That said, your car is making way more noise than is typical from that system. Usually you just hear a steady "tick, tick, tick" for awhile after shutting off the car.

[newguybugeye]

Hmmmm forgot to mention, it was going on and off for about an hour before it stopped. Doesn't seem like that would be the cooling system?

Also, when I connect/disconnect the battery it stops momentarily then starts up again...