I drop off my car at the service department to get...

I drop off my car at the service department to get a check engine light diagnosed. The guy at the counter said it would be one hr labor to tell me exactly what's wrong so I said that's great! so I dropped it off. He called me the next day with the diagnosis and said the balance shaft was stripped which is a known problem for this M272 and m275 Engine. But I told the guy it was just replaced Last week so he had there technician check it again the next day. So the next day he called me back and said the chain maybe stretched. ( So basically I paid one hour diagnosis for a guessing game ) it takes less than an hour to check and see if the timing is off or not. I would recommend you TAKE YOUR MONEY ELSEWHERE