I'm at 94k miles and my down shifting is starting to get a little irregular. When I'm decelerating, my RPMs spike up and goes down then spikes up again and then goes down. I have a 2004 530i auto. Any ideas
Thanks.

 

try resetting your tranny by holding down your gas pedal with the key turned just one click in the ignition

 

I came across a post about that when the issue started and I tried it but not luck. It's still doing it. You think maybe its the spark plugs?

 

I would most definitely change the spark plugs if you haven't done that yet? Also think about changing the trany fluid.
Have you ever done any of these two services on this car?

 

No, I've had it almost about a year and half and keep with all the all the i-Drive alerts but thats about it. I found the DIY on changing the spark plugs but coudnt find anything on changing the tranny fluid. Also, is there a specific brand of spark plug that will give maximum performance?

 

BOSCH are the OEM but many members have changed them with NGK. Both would be fine.
I personally like NGKs better.

 

had the same issue... 60k service fixed this issue. plus better gas consumption... keep me posted if this is the issue