[SfValley335i]

I got a 6mt 135i n54 with only 30k miles. I'm FBO... The car drives fine power wise, there is no vibration or noise inside the cabin on hard acceleration in 1st or 2nd gear.

However, under hard acceleration in 3rd gear or higher 60mph+ , the car has this annoying vibration, it doesnt shake the car but sounds like a car with really stiff engine mounts... Sounds like "Vrrrrrrrrrrrr"

The car shifts and accelerates fine, I'm clueless at what could be wrong or what to look for.

Im out of warranty so I do not want to pay the dealer a visit...

Any ideas on what to check would be appreciated.