davek9

"...And a weird buzzing sound is almost semless but steady...", if the sound is only when the engine is running and coming from the Dash, it is most likely a Vacuum leak somewhere w/in the HVAC system.

Good to hear you are going to re-check the Tbelt and find the cause of the alert, please follow up w/ what you find.

James Bailey

The "inspection by a 928 specialist " really means nothing....did he check tension with the Porsche tool ?? While it is possible to get false readings it is very foolish to ignore one. If it was my car I would not even start it again until I KNEW everything was OK.