This customer came in complaining of a clunking sound when accelerating hard. I found that some of the bolts between the motor mount and the engine were sheered off. This is rather common in BMWs. The whole engine was shifting when he accelerated hard.
Many of the bolts in BMWs are made from aluminum and need to be torqued to a very specific torque which allows the bolt to stretch and clamp 2 parts together. If you tighten the aluminum bolts too much they can stretch too far and won't clamp, or they can break prematurely.
I had to very carefully work each broken bolt out to avoid having to drill them out. Luckily, I got all the bolts out without having to drill anything and was able to install and torque the new bolts without any trouble.
No more clunk.
Need a battery for your BMW? We install genuine BMW batteries. Careful with having the local parts store install a battery. Many BMWs need to have a scan tool reset the computer so it doesn't overcharge the new battery. If the computer isn't reset it can result in a shortened battery life or even a fire if the battery is overcharged too much.
I have a scan tool than can reset the computer.