I currently own an early M20 525i, and it's got a lot of problems. I was wondering what you know specifically are issues that show themselves in these, later model E34s, specifically the 540i.

When I search online, all I seem to find is wrong information from people using E39 issues and applying them to the E34. I already know what goes wrong with the E39 540i and E38 740i, but I am curious about the E34 specifically.

Besides the Engine linings, what else is common?
The biggest problems in my E34 are electronic issues due to the clusterboard going , and nobody seems to be able to repair it. (I even bought some replacement boards, but it seems like most of the people rebuilding them have given up rebuilding and just send out bad boards from old cars, because he sent me two bad boards which were plagued with completely different problems - yet the problems were all rooted in the board.

Next, is the coolant leak from the old heater core. This is a big problem in all E34s, so obviously not specific.

The electronic issue seems to be the biggest pet peeve of mine at this point.