E30 Zone

Hi, thanks in advance for any help! It is greatly appreciated.

I have an '87 325es and stock sound system (which is still very impressive!). I use the tape deck for a tape with MP3 jack and plug it into my iPod and it works great - except for one thing. With seemingly no rhyme or reason, it switches from "1" to "2" - which I assume means side 1 of the tape to side 2 of the tape, every couple of seconds for minutes at a time. This is very annoying as the music cuts out every time it switches.

I thought it was maybe because it thinks one side of the tape is finished so it switches to the other side, but I was wondering if anyone knows why this may be happening or how I might go about avoiding it.

Once again, thank you very much!

Pushing it a bit for an E30 tech query, but there will be a peg or roller that pushes into the tape as it travels past the tape head (two, maybe; one each side), and is forced back when the tape goes tight at the end of a side.
It's possible that your adaptor doesn't have provision for this peg or roller, and is being permanently held back in a position where it trips the reversing shuttle.
Probably a bit of surgery in the correct place on the 'tape' housing will cure the problem.