It looks like the broken headbolt issue only occurs on 1990-1992 (1993?) models. I am not aware of this problem on 88-89 and 94 models. Recently checked mine ('88), no problem whatsoever.
The loose banjo bolts can occur on every model. I had the same problem and discovered it by looking at the lubrication of the camshaft with a running engine (removed filler cap). Normally you would see a nice flow of oil squirting onto the camshaft, but in my case it was just a few drips every 3 seconds.
I was planning on replacing my valve stem seals anyway, so I pulled the manifolds and the valve covers to find out 3 of the 4 banjo bolts were just barely fingertight.
Removed the oil spraying bar, used compressed air to blow out the tiny holes and reinstalled the banjobolts with locktite. Now the oil supply to the cams is better than ever before, I noticed the difference before and after the repair while looking at the camshaft with a running engine.
If you want to know more about this procedure, check our website section fixes->engine->valve stem seal replacement.
http://bmwe32.masscom.net/
Cor hat es so gemacht bei der Motorueberholung
http://bmwe32.masscom.net/sean750/en...0rebuild_1.htm