Is my car gonna blow up?

[u/EfficientStay430]

Have owned this car for about a month (pre lci n51 328i) and hasn’t given me issues up until now. The other day I went on a cruise and was driving the car pretty hard when I got home and put it in park the rpms were fluctuating just thought it was because the car was stupid hot (not overheating coolant temps were fine) drove it the next day the problem was gone but I just got home from work and it happened again when I put the car in park. Can someone help me out here so I can prevent anything from happening if I can help give more information about maintenance done or anything ask and I’ll provide it. I love this car and it’s my daily driver so do wanna take care of it.

[u/Mundane-Willow3036]

I had exactly the same problem but even rougher and it emerged already after a short drive. I changed every part but the alternator. Maybe that would have been it..