from wut i know it sounds normal. especially its only doing for 10 seconds, if it was a real problem then the sound would go for as long as you have the car on for. it sounds like ur fan. it turns on and then shuts off after cooling. does this happen all the time or when you drive alot? the fan sometimes doesnt turn off eventhough you have the car off so it cools thigs down. next time just to double check pop ur Hood
open and then listen to where the noise its coming from. the fan noise should be coming from the front by the radiator and should sound like voom and then turn off and you can still hear it for a few more secs after turning off. no metal to metal noises.