10 Things You Need To Know Before Buying An E63 BMW 6-Series

In the mid-noughties, many column inches and forum posts were dedicated to lambasting the work of Chris Bangle. BMW‘s design chief from 1999 to 2008, Bangle’s designs were criticised for being too fussy and in some cases downright awkward, but these days, the man’s work is looked upon much more fondly.

Granted, the downright bizarre styling shock tactics BMW is currently going for make us yearn for the days of Bangle and his ‘flame surfacing’ more than we might otherwise, but for the most part, it’s simply that Munich’s products from the era have aged brilliantly. Arguably the one to wear its years the best is the ‘E63’ 6-series, which just happens to be an utter bargain right now.

Prices of the earliest examples have started to level off, so now is a great time to buy. Of course, low prices do mean many are in the hands of less than fastidious owners who won’t bear in mind that this is a car that cost the equivalent of £80,000 when new. You simply can’t run one on a shoestring.

The usual depreciated luxury car rules apply here - look for a full-service history, and be prepared to budget a decent amount of money for future remedial work. That said, E63s are easier to work on yourself than you might imagine, and although they’re weak in some areas, the 6er is plenty robust in others.

Here’s what you need to know before taking the plunge:

The inline-six is the safest bet

You can’t go far wrong with the 630i. The 3.0-litre inline-six is as tough as old boots, easy to work on, and makes a decent din. You’re looking at 254bhp from the earlier N52-equipped models and 272bhp with the later models fitted with the N53, making for a 0-62mph time in the six-second range.

That’s more than enough for most, and as the lightest 6-series with a kerb weight of around 1500kg, it’ll be the best handling. It’s also the only one you can easily find with a manual gearbox. Common failure points are generally quite painless - these include cracked coolant pipes and failed coil packs.

The N52’s ‘M57’ diesel counterpart develops a similar amount of power but a lot more torque. It’s a relatively safe bet too, but be wary of failing thermostats that make the unit run cold, clogging up the diesel particulate filter (DPF). Broken swirl flaps in the intake manifold have been known to fail and cause serious engine damage, but these can be removed with an aftermarket kit.

The V8 is lovely, but potentially problematic

Less risky though the six might be, it’s a V8 that best suits the 6-series’ character. Unfortunately, the N62 is a troublesome brute, whether you go for the earlier 4.4-litre version in the 645ci or the 650i with its 4.8.

Most of the N62’s issues surround seals. Easiest to spot when leaking are the rocker cover and upper timing chain cover gaskets. One that can go unnoticed on the other hand is a seal near where the alternator is mounted to the block. It’s up to 10 hours labour to replace it, and if left too long, oil will leak into the alternator and kill it.

Worst of all are the valve stem seals. The official oil change intervals are arguably too long and make the problem worse - if they know their onions, the previous owner will have renewed every year/10,000 miles. Be sure to take a close look at the service history for evidence of this, and also check the state of the exhaust gases. Do a cold start, idle until warm and then rev - blue smoke means those stem steals aren’t happy. An independent garage will charge up to £2000 to replace them.

The most notorious N62 issue regards the coolant crossover pipe. It sits between the cylinder banks, meaning the consequences of a serious leak (common at around 80,000 miles) can be catastrophic. BMW in its infinite wisdom designed the original part in such a way that the engine has to be removed to make replacement possible, but there is now an aftermarket design that can be installed with the V8 still in place. It’s still a fairly hefty job, though.

If you’re after more power, an even better engine note and more potential for big bills, there’s the V10-powered M6 to consider, but that’s one to cover in detail another time.

Dynamic Drive improves handling but might not be worth it

The 6-series was originally available with a ‘Dynamic Drive Pack’, which added hydraulic anti-roll bars and a variable-ratio steering rack. The option noticeably sharpens up the 6-series’ handling, which is a fairly boaty thing to drive otherwise. We’d be tempted to avoid 6ers with it fitted, though - if it goes wrong, big bills are guaranteed.

Gearboxes are strong

The ZF-supplied six-speed automatic fitted to most E63s is reasonably robust, and although it’s technically ‘sealed for life’, you can and should have the ‘box serviced at 100,000 miles. Most M6s have the seven-speed SMG III robotised manual gearbox (a small number of US-spec cars got a six-speed manual).

A six-speed SMG was available on the 630i, 645ci and 650i, but avoid those like the plague. All 6ers apart from the 635d could be specced with a six-speed manual, but don’t get your heart set on one - they’re extremely rare.

Watch out for blocked drainage holes

There’s a quartet of drainage holes between the engine bay and the bulkhead which are for expelling water that rolls down the windscreen. At least that’s what they’re supposed to do until they inevitably get clogged with leaves and other debris.

Left unchecked, water can enter the cabin, soaking the carpets and potentially damaging electronics. On the E64 convertible, there are additional drainage points behind the roof which can suffer the same fate.

The body is fairly solid otherwise - the worst you should get is a little rust around the rear arches. The front wings and boot are made from carbon-fibre reinforced plastic, while the doors and bonnet are aluminium. Be wary of damage to the latter, given the more painful repair costs associated with the material.

The chassis is pretty solid

The chassis is nothing particularly exotic since most components are carried over from the E60 5-series. It’s all the usual stuff to watch out for - nasty knocks and steering play pointing to banjaxed bushings, and juddering caused by warped discs or pad material transfer. On the latter front, it’s best to stick to either OEM braking components, despite the additional cost.

Check iDrive is working

The E63 got one of the earlier versions of iDrive (upgraded to the third-gen ‘CIC’ unit from 2008), which is more useable today than you might imagine. These have been known to fail, however, getting stuck at the boot-up stage. If the system is laggy, it may be on its way out. There are aftermarket replacement systems kicking around with Android Auto and Apple CarPlay compatibility.

On the subject of infotainment, if you’re into music, you’ll want the Logic 7 sound system option. An easy way to tell if a 6er has this fitted is by looking for the rear quarter panel-mounted speakers.

An exhaust should be on the top of your mods list

With much of the range featuring naturally-aspirated engines, for the most part, there aren’t easy power gains to be had here. What you might want to be doing, particularly on the V8 models, is improving the soundtrack.

The N63’s sonic potential is squandered by the stock pipes, although this isn’t really BMW’s fault - exhaust systems were much simpler back then. You’ll need to budget about £2500 to change both back boxes and the ‘X-pipe’ centre section.

Even the newest E63s out there are now almost 15 years old, so springs and dampers will likely be tired. While replacing components, you might wish to go for a lower, stiffer setup to remedy that boaty handling mentioned further up.

The one exception for big performance increases on the cheap is the 635d. The M57 inline-six turbodiesel can be reliably remapped from its stock outputs of 280bhp and 428lb ft of torque to around 360bhp and 520lb ft - enough thrust to give the 650i a run for its money.

Make sure you choose the right tyres

BMW came in for plenty of flak back in the E63’s day about the ride quality of the run-flat tyres it chose to fit on many models. Should you want to stick with them (which you might well, due to the lack of spare), though, the Pirelli P7 Cinturato rides nicely.

If you’d prefer to go for something else, the optional 19-inch 595-design wheels commonly fitted can be shod in ‘ultra-high performance’ or ‘UHP’ tyres like Goodyear’s Eagle F1 Asymmetric 5 for only a little more than most mid-range options.

For a full set, it’ll be around £700 fully fitted. You could spend more and go for a ‘UUHP’ tyre like the Michelin Pilot Sport 4 S or Continental’s Sport Contact 6, but that’s potentially overkill considering the E63 is more GT than sports car. Size-wise, you’re shopping for 245/45/18 all round (592 design wheels), 245/45/18 front and 275/40/18 rear (593) or 245/40/19 front and 275/35/19 rear (594, 595).

Prices start at £2500, but spend more

E63s tend to start at about £2500, but for that, it’ll be a very leggy 630i. Up your budget £5000 or so and it’s possible to find a tidy 645Ci, while a couple thousand more should be enough for a nice 650i. Expect to pay upwards of £15,000 for an M6, with a few thousand more kept in reserve as a contingency budget for when something expensive goes pop.