Q: I the 2011 BMW 328I recently changed the radiator and fan and put in the wrong coolant.

Using the wrong coolant shouldn’t have any short-term effects like that. The consequences of using the wrong coolant usually relate to seal and head gasket failures over a long period and if you have replaced it, everything should be fine. Your hesitation may relate to the work you did, or it might be something else altogether. I would re-visit all the work that I did to see if there is a ground wire, or an electrical connector that isn’t connected properly or maybe a vacuum hose that got damaged or pushed off during the operation. If you don’e find anything that way, contact YourMechanic. They can send a technician to your home or office to check out your hesitating BMW and let you know what is the solution.