To let you e53 4.4i / 4.8is owners know, there is an open SIB regarding the parking lock pin on the transmission being faulty. The fault is such that the pin becomes misaligned due to the material the mechanism is made of causing a distortion and poor lock. The result is a runaway vehicle on an incline.

There are other BMW’s affected, but for the e53, it will be the 4.4i and 4.8is with the 6HP26 transmission. I found out the not-so-fun way while in Seattle the other day. Leaving a parking garage, I had to stop on an incline and get out to open the garage door. I put the truck in park, with the e-brake on. Got out and took three steps. A loud bang/clang followed by the truck beginning to roll forward. I was able to jump in but by that time it had rolled enough to hit a barrier causing damage to the passenger side aero bumper. The park mechanism and e-brake could not hold the weight of the truck.

I backed up and while in the truck verified that the truck does indeed roll forward in park.

I highly suggest if you’re curious that you find a steep incline, put your truck in park and see if it rolls on its own.

I called my local dealer and spoke with a rep. So far everything regarding the SIB checks out and I am scheduled to drop it off in a few weeks. I’ll let you all know if BMW NA still honors this SIB while it is a serious safety issue.

https://static.nhtsa.gov/odi/rcl/200...5V504-9534.PDF