Ok, I think you have a multitude of problems all at once here. First thing is to check fault codes with the stomp test and see whats going on there. Thats probably the hesitation deal.
The over heating could be the auxilliary fans or the clutch fan needs replacing.
The dash problems are probably a couple of bad capacitors you will need to solder and replace.
Hope this helps you isolate some of your problems.
95 E34 530I V2.37
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