Squealing noise from engine block when off.

[Gamb1t]

Noticed lately that after I parked the x1 there is this intermittent high pitch squealing coming from the engine block. It comes on after few minutes. The car is switched off.
This doesn't happen at idle or anything.... Only after turning off.

I know there are off nose here and there...pump priming or something. But this squealing is new. It doesn't always to happen all the time and goes away after awhile making it difficult to diagnose. But definitely under the engine cover.
Truly baffled.

X28i...n20.

[cwickberg]

thermostatic fan going bad?

[e36addict]

Probably hearing the electronic throttle body doing it's cycle. It is very random. Sometimes mine "wakes up" randomly and does that. Lasts maybe 3 to 5 seconds. Completely normal if that's the case.

[Gamb1t]

Thanks for the response. It has not come on lately. This continues to baffle me. I can trace the sound coming directly under the engine cover. I'd like to drive without the cover to confirm the location but there is vacuum line connected to it.