Yo Man! Its great to hear that another 535i E34 lurkes in the wilderness....hahaha
anyway down to business:
1. Congrats on the great choice of car! (Its a true highway cruiser - it will run circles around any japanese car at sustained speeds of 200plus kph on the highway all day all night long)
2. The 3.5 litre M30 is a bulletproof engine when maintained carefully. i.e. fully syn engine oil at every oil change + a properly maintained cooling system i.e. thermostat, hoses, coolant, radiator cleaned etc etc...will never see an overhaul for quite some time.......well into the 300 thou km mark......
Weak points for engine are:
1) Headgasket if the cooling system isnt maintained as scheduled
2) All rubber hoses (intake manifold, fuel regulator, oil breather, idle valve, fuel and vacuum hoses) get hard and crack. Its a hot engine - check out the size of the radiator and you'll understand why?
(but not to worry there are tons of silicone high temp hoses to choose from all of which will last the lifetim of the car - buy once and leave it so no worries there.
3) AirFlow Meter (It uses that stupid mechanical flap which tends to bind with dirt and require servicing and tuning to keep it in check) but not to worry there are readily available hotwire AFM conversion upgrades.
heh heh
Weakpoints for Drivetrain are:
1) Auto Gearbox - Dont rev that thing in neutral or park koz it'll wreck itself to bits! and change your ATF regularly!
2) Manual Gearbox - Can't say koz i havent delt with one b4?
Weak points for Suspension are:
1) Rear subframe bushings - Tend to crack after wear and resulting in a clunking or rear end odd steering wheeling (
2) Front end shimmy under braking. Suspension arm bushings are undersized for a car of this wieght and once wear are very annoying koz the damn car starts doing funny things.
(Not to worry, once again there are thousands of polyurethane bushing upgrades to eleminate this problem entirely)
Electronics:
1) Your Display console will tend to go bonkers if its old.....those capicitors, diodes and other funky shit will tend to crack and get funky wid age resulting in all sort of electrical gremlins like your rpm meter moving by itself when stationary....etc etc...
2) Fuses, Relays, Wire Harnesses