What to look for when buying an BMW e31 8 series. The buyers guide.
The 850 was one of the most subtle super-GTs, with a remarkable 0.29 drag coefficient. This ultimate autobahn-stormer could cruise all day at 150mph, delivering the driver relaxed to their destination thousands of miles later.
Never really a sports car, even when BMW added a six-speed manual 'box and M-technic suspension as options, it came closer when the phenomenal CSi was launched in 1992 - after which the 840 joined the range as the entry-level model.
The ultimate Alpina B12 5.7 manual boasted 416bhp; there was also a B12 5-litre automatic with 350bhp. The majority were 840s and most were automatics.
Official figures show that 3040 came to the UK, of which 850 were V12s. DVLA records cast doubt on that, showing 1215 V12s registered in 1999, but, equally surprising, just 306 left in 2011. Some have been crashed and others broken for spares, but surely not so many?
Of the V8s, the DVLA's highest figure was 2001 cars; now it's 1259, a more plausible depletion rate.
They are extremely tempting as a classic buy. Prices have shot up in recent years, but you can still get a rough 840 or 850 for under £10,000, and a good one for less than £20,000, and cars of at least 20 years old are eligible for cheap insurance.
The 4-litre is arguably the best value, often better equipped than the 4.4s. Though officially limited to 155mph, most cars will go faster. Of course, the more complexity, the greater the danger of getting your fingers burnt but, because these cars were so well made, if you find one that has been properly maintained and cherished, there is little danger of being hit by horrific bills. That sub-£10,000 car, however, could easily cost another £10k to bring back to a decent standard.
Corrosion, check for poor past repairs and, if the paint is fading, remember that resprays are not cheap. High mileage is rarely a problem: neglect is the main enemy and irregular use can wreak havoc, especially if the car is stored in damp conditions.
And don't be taken in by a vendor saying: "The dash displays aren't working, it's probably just a fuse." More likely, he tried to jump-start it and blew an £800 control module. Boffins can rebuild them for less, though it's still a costly repair.
The heart of every 8 is a superb V12 or V8 engine. Look for oil, water and clutch-fluid leaks, plus non-standard parts, signs of tampering and recent major work that may not have been done properly. Fully synthetic oil is best avoided: it's too thin and is consumed rapidly. A full service history is a big bonus, reflected in price.
If water level drops, air locks form and need a specialist fix - otherwise head gaskets can blow, leading to major problems if not repaired promptly.
Automatic gearbox problems are rare; its specification is better on later cars. Manuals can become notchy, though this can be rectified for £700-1000.
Most driver's seat side bolsters have worn through, and the foam behind often breaks down. Budget £250-350 to replace worn panels and re-colour.
Most dash displays have lost pixels: a repair costs c£80; replacement c£330. Check that it all works: a jump without spike protection kills costly electronics.
Check pop-ups operate and reflectors are in good order. Dipped beam is very poor; HID upgrade with ballast in loom transforms it from £250.
These were some of the first cars with 'fly-by-wire' throttles. They are packed with ECUs, each of which can cost hundreds, if not thousands, to fix if they fail. Viscous fan, water pump and cam-cover gaskets are common failures, needing hours of work to replace. Beware oil leaks from the upper and lower sump, plus timing-cover gaskets on V12s: £1500 minimum to do the lot.
Engines are immensely durable. The Nikasil liner problems on 4-litre V8s have virtually all been sorted and 180k miles without problems is not unusual; some V12s are up to 220,000 miles.
To check for a misfire, select park/neutral with the engine warm and ticking over, then floor the throttle and lift off - as the revs rise, listen for an uneven note. On the test drive, doing 30mph, accelerate hard and look for smoke behind. Poor running is often down to ageing Lambda sensors or throttle bodies out of sync, though it could be valves, stem seals or low compression.
The brakes should be excellent, but calipers stick on infrequently used cars. Automatic Stability Control units can leak - replacement is £3000 unless you can find a second-hand one. On a CSi, check that the rear steering works; you can feel it on roundabouts or tight corners. The £3k actuator solenoids seize, but can often be freed.
Check out my e31 s62 build • BMW E31 8 Series with ...
⛔ Stay tuned by subscribing as I will be doing more in depth videos of the E31 and few other retro/classic bmw models.⬇️⬇️ bit.ly/3rCw1B4
⛔ More interesting cars on my Instagram ⬇️⬇️ / bmwrestored
#BMWE31 #8series #bmwe31buyersguide