Hi, Doug here. I've had my 523i E39 for about 10 months now, and I've become very familiar with forums after experiencing just about every one of their known foibles. It's a 1996 with rumbling rear wheel bearings, an engine with a slate-grey deposit in the coolant, overheating, starting problems when warm, etc. So I now have a selection of pullers, and other tools all ready to sort it out. I made the mistake of assuming a low mileage car with full main dealer history would be a safe bet, it's a steep learning curve.
It failed the mot on the rear wheel ball joint, and the garage didn't want to know, so I bought the puller and did it myself. I now have a 328i engine on a pallet waiting to be fitted, and an M50 manifold in the shed, so as you may have guessed, none of the above has put me off the car. My plan is to fettle the spare engine and sort out the manifold conversion, so that when I fit it I'll gain such a big improvement I'll think the effort was more than worthwhile.