Buying Guide 6-Series E63/E64

It’s amazing to think that BMW’s glorious 6 Series Coupé has been with us for 14 years now – especially given that I attended the international launch of the car, and can remember it like it was yesterday.

Based in southern Spain, and with a plethora of 645Cis to test on the sinuous roads that run up from the Costa del Sol to the historic town of Ronda, it was one of those launches that really stuck in the memory.

INITIAL SHOCK

The car might have been a little bit of a shock on the styling front but, after the E65/E66 7 Series and the E60/E61 5 Series had both made their debuts, we were all starting to get the hang of these differently-styled BMWs. While it was still a little ‘out there’ for some tastes, the assembled journalists reckoned the new 6 Series was a bit of a looker.

Under the bonnet was a stonking V8 and, coupled with excellent road manners, it became something of an instant hit. It was a £50k car before any options had been added, but the good news for those wanting some stylish transport today is that you can now pick up a very decent example for a tenth of that figure. Or even less, if you’re feeling very brave.

Like all luxury cars that have been subject to some rampant depreciation, the 6 Series has, to a certain extent, fallen into the hands of those who can’t really afford to maintain it. It’s not that regular maintenance is particularly exorbitant but rather that, when problems and faults do occur, they’re expensive to sort out.

GREAT DRIVE

But when an E63 (or the Convertible E64) 6 Series is running properly, it’s a joy to drive. During its lifetime, several engines were offered – two V8s (645Ci and 650i), two straight-six petrols (the 630i featuring both the N52 and N53 units) and the 635d, which didn’t arrive until the car underwent its facelift in 2007.

But, no matter which engine is fitted, the E63 can make a wonderfully wafty cruiser, while also having a pretty good crack at being a sports car, when the mood takes you. The 645Ci (both in coupé and convertible forms) arrived in March 2004 and they both featured the 4.4-litre Valvetronic V8 that had made its debut in the 745i, and it was a cracking powerplant. Vital stats were 333hp at 6,100rpm and a torque peak of 332lb ft at 3,600rpm, which endowed the Coupé with performance figures of 0-62mph in 5.6 seconds for the manual, and 5.8 for the auto version.

Top speed was electronically limited for both models to 155mph, and BMW claimed a combined economy figure of 25.9mpg – not bad for a grunty V8. The technology under the Six’s skin was borrowed from the new 5 Series and the E65 Seven and, suspension-wise, it was as per the E60 Five.

Its excellent performance and economy were, in part, down to the extensive use of lightweight materials; the front wings and the boot lid were of ‘Sheet Moulding Compound’ (posh plastic, to you and me), while the bonnet, doors and many of the chassis components were crafted from aluminium. All of which meant a kerb weight of 1,615kg, which was pretty good for a large coupé.

The 630i joined the line-up in late 2004 and, despite ‘only’ having 258hp, it was almost as quick as the 645Ci (in manual form at least) and, with a lighter engine, it weighed a significant 130kg less than the V8-engined machine. This made it a pretty tidy handler, and a good option for the keen driver. It was significantly more economical, too.

The 635d was the last Six to be launched, back in 2007 and, while diesel coupés are all too common nowadays, at that time it was seen as quite a radical alternative to the petrols. With the twin-turbo ‘six from the 535d under its sculpted bonnet, the 635d could muster a 6.3-second 0-62mph time, yet was also capable of returning over 40mpg on the combined cycle.

ENGINE WOES

While the engines fitted to the E63 generation of 6 Series are pretty good on the whole, there are a number of things to look out for. Let’s start with the entry-level 630i, to which BMW installed the N52 lightweight six-pot, as well as its N53 272hp successor. They’re both strong units but do have a couple of Achilles’ heels. It’s easy to tell the two units apart – the N52 has a silver-coloured, plastic engine cover, while the N53’s cover is black plastic.

The N52 can suffer from wear in the camshaft housing in the cylinder head, where a steel-sprung ring sits, acting as an oil seal. This can eventually wear a groove in the cam carrier, allowing pressurised oil for the Vanos unit to escape. It’s often diagnosed as a Vanos fault but, be warned, repairing the head is a very expensive business.

Preventative maintenance should involve replacing the oil frequently – every 8,000 miles, or once a year is preferable to following BMW’s Conditioned-Based Servicing. The N52 is also keen to leak oil from its cam cover gasket, and its electric water pump is expensive to replace –­it’s over £500 for a genuine unit.

The N53 doesn’t suffer with the same cylinder head trouble, but it can be affected by running faults, generally related to injectors, coils, its high-pressure fuel pump and NoX sensor. Repairs here can very easily run-up a bill £1,000+ – genuine injectors are more than £200 each, and they need coding to the car, too.

V8 VULNERABILITIES

If the problems that can beset the straight-six models have you looking towards a V8-engined 645Ci or 650i, be warned that these units are by no means bulletproof, either. One of the most expensive potential repairs relates to the valve stem oil seals – look for clouds of smoke from the exhaust after the car has been idling for a few minutes… although this can also be the result of a failed crankcase ventilation system – the oil separator valve and its rubber pipes – or leaking cam cover gaskets.

Stripping the engine to replace the valve stem seals in the traditional manner is prohibitively expensive –­but the job can now be done with a special tool, which brings it down to a more palatable £1,500 or so, and it can be attempted by a keen DIY mechanic, too.

The other main problem with the N62 is a coolant tube whose sealing fails with time. The official repair involves the engine coming out and having an almost full stripdown, but the leak can be repaired using an expanding coolant tube that was developed by the aftermarket. It’s still not cheap though – a specialist will likely charge getting on for £1,000 to make this repair.

While some improvements were made to the engine for the N62N 4.8-litre (as fitted to the 650i), not all the failing points were addressed. So always make sure that you check over any V8 very carefully. It must idle smoothly and not smoke when left running stationary for a while.

Once it’s been idling for a number of minutes, give the engine a rev and, if there are clouds of smoke from the exhaust, either negotiate hard on the price or walk away. Ideally, you’d want to find an example that has had both its coolant tube and valve stem seals replaced already, or budget for their replacement when you’re buying. A car that’s been well looked after – and has had frequent oil changes – is less likely to suffer but, generally with the N62 V8, it’s a case of when, not if, the faults will appear.

DIESEL DILEMMAS

While there’s no doubting the diesel suits the E63 very well, and the promise of 40mpg looks attractive, the twin-turbo six isn’t without its troubles. Timing chains are generally reliable, but swirl flaps aren’t and should be removed if they haven’t already been whipped out. Vacuum pipes can become blocked, which leads to running problems and premature turbo wear – replace or clean out on a regular basis. Ditto the EGR valve.

One of the major worries on a 535d is turbo wear – ­a pair of turbos for a 635d will set you back nigh on £3,000 from BMW, and that’s before fitting! You can go ‘aftermarket’ but, even then, you’ll be looking at over £2,000 to get this done.

Diesels are also pretty sensitive to having correctly-working thermostats; if they’re not, economy will plummet and the diesel particulate filter might not get hot enough to regenerate. Fortunately, they’re not expensive to replace.

TRANSMISSION TROUBLES

The E63 could be spec’d with three different gearbox options, all with six forward speeds. The automatic was by far the most popular, with the manual coming in a distant second and (thankfully) hardly anyone ever opted for the SMG version – it was rather clunky and not all that reliable. The manuals are more or less bullet-proof, and don’t seem to burn out clutches and flywheels all that often.

The six-speed auto is also a pretty reliable unit, although I’d always advise some preventative maintenance. BMW billed the auto as a sealed-for-life unit, but treating the ‘box to some fresh oil at around the 70k mile mark is always a good idea – it’ll change more smoothly and last longer.

The gearbox sump also has a habit of warping and leaking so, if you’re experiencing a harsh change, it’s likely that the ‘box is running low on oil. Get it attended to as soon as possible. It could also be a software-related fault, but always get the fluid level checked first. A new sump and an oil change should cost less than £500.

Occasionally you might experience a fault with the mechatronics unit in the ‘box, but these can now be repaired. Differentials are strong (but do check for pinion and output oil seals failing), as are driveshafts.

ELECTRICAL GREMLINS

BMW packed a lot of tech into the E63 6 Series, so it’s worth checking that it all still works. All cars will have iDrive and 95% of them also have satellite navigation, mostly the upgraded, Professional version with larger screen.

Pre-facelift cars will have the CCC system that’s DVD-based, while later models use the CIC system – check that both work correctly, as a failed DVD drive will be expensive.

Like many modern BMWs, having the correctly-sized battery and having it coded to the car is absolutely vital, and any number of electrical faults can be traced to an incorrect battery, or one that’s on its last legs. Assuming the battery is in fi ne fettle, many other maladies can be cured by having the latest software installed.

Radio antennas can fail, electric windows can refuse to drop when opening the car, and air conditioning systems can fail thanks to faulty condensers or compressors. So spend as long as you can checking that everything works – it’ll pay off if you find something that’s exhibiting a glitch.

STRONG SUSPENSION

The Six’s underpinnings are more or less identical to those on the E60 5 Series and, in general, it’s a pretty tough set-up. Naturally enough, items can fail over time, but nothing underneath is hugely expensive to replace so long as you keep on top of it – having to replace several worn components at one time will be slightly wallet-wilting, though.

The aftermarket caters well for the car, with most arms, bushes, springs and dampers being available ‘off the shelf’ from companies such as Euro Car Parts. What’s more, buying Boge Sachs dampers there will be significantly cheaper than at your local BMW dealer.

There are two options to be avoided, though, and they are the Dynamic Drive anti-roll system and Active Steering. Both can be fearsomely expensive to repair and, to be honest, don’t really enhance the driving experience to any great extent.

There are few horrors to be encountered with the E63’s brakes as the all-disc set-up works well. Obviously, though, have a look at the car’s history to see when pads were last replaced, and budget for a set of new discs at every second pad change. The ABS and traction control systems generally work well and without problems but, if you can, have a look underneath and assess the condition of the brake pipes as, on cars of this age, corrosion can be an issue.

Inside the E63 you’ll need to check the condition of the leather, and make sure that all the trim is present and undamaged. While many cars were Sport models, there’s little to distinguish these externally. But all Sports have the desirable Sport seats, identified by the front bolster that extends out further, towards your knees. Make sure the electric seats move in all directions as motors can seize up from lack of use.

If the car has the panoramic sunroof, check that it tilts properly (sadly, it doesn’t actually slide back at all) and, when on a test drive, make sure it doesn’t rattle. It should go without saying that you should check the operation of the hood on any potential Convertible purchase and, also make sure that the odd vertical rear screen goes up and down properly. Any hood problems are likely to be due to faulty motors or micro switches – repairs at main dealers are expensive, but reconditioned hood motors can be bought from around £350.

While you’re inside, check that the carpets aren’t wet; blocked drain holes in the front scuttle panel can cause water to leak into the interior.

BODY BEAUTIFUL

The looks were certainly controversial when new, but the E63 has grown into its Adrian van Hooydonk-penned lines very well, and it’s a very handsome machine today that stands out among increasingly bland modern designs. The good news for buyers is that there’s very little to concern yourself with regard to bodywork, other than looking for stone chips and any obvious accident damage.

The mix of plastic, steel and aluminium used for the body doesn’t degrade over time so, apart from looking at paint match between panels and consistent panel gaps, there’s very little to worry about. However, do examine the headlights for both damage and condensation, as they’re notoriously difficult to dry out and expensive to replace. Also check the xenon light is consistent between units; a dimmer one can indicate one that’s on its way out.

Give the wheels and tyres the onceover, too, checking for a matched set of quality tyres. If the car’s sitting on worn-out no-name tyres, you have to ask what else the owner’s skimped on? Many will still be on run-flats, while some owners will have ditched them in the quest for improved ride quality.

While there’s plenty to go wrong on an E63, if you can find one in fine fettle, it can be a very rewarding drive. Don’t make the mistake of thinking it’s a full four-seater, though, as the rear seats are really only for occasional use.

Do your research carefully and have a look at as many as you can before taking the plunge, and you’ll bag yourself a super cruiser that can double as a sports car when you want it to. What’s more, if you buy wisely, it shouldn’t even depreciate that much more, either!

WHAT TO PAY?

E63 ownership can start as low as about £4,000, but I’d advise against this end of the market. It’s likely that cars at this price will need the same again spending on them to bring them up to snuff.

You can find some 645Cis worth considering at £5,000-£6,000, but sorting the wheat from the chaff will take some doing. Look for cars with few owners and lots of history, including some preventative maintenance.

Upping the budget to £7,000-£8,000 should secure you a 630i with the N52 engine, that hasn’t been to the moon and back, while £9,000-£10,000 will buy you a 272hp, N53-engined example.

With the 635d being slightly newer, you’ll need to spend the best part of £10,000 for a decent example with less than £100k on the clock. As a rule, I’d avoid those that have been remapped or tuned, as it’s an expensive engine to repair. If you prefer the security of buying from a BMW main dealer, then there are still some late models available, with prices starting at about £13,000 and rising to £18,000 for a low-mileage 635d Convertible. I certainly wouldn’t want to pay more than that though as, by that price point, you’re getting into F12/F13 territory.

OWNER’S VIEW: ELIZABETH DE LATOUR

“After four years of company cars, I found myself in a position where I needed to buy a daily but, with no commute, it didn’t have to be too sensible. After deciding on an E92 330i I realised that a 630i cost about the same, had almost identical performance and economy but was undeniably more special and, as I’ve always loved large, luxury GTs, I bought one.

“There are a lot of things I love, starting with the styling. It’s a very well-proportioned car and it looks elegant and graceful. I love the Pearl leather option that mine has, which makes the interior feel really special. Most of all, I love the engine; the N52 is a peach. It’s fabulously smooth, torquey, sounds great and loves to rev. It’s significantly lighter than the V8, making the 630i a much more involving drive.

“Problems? Well, I’ve had a few… My iDrive’s DVD drive failed; the pano roof squeaks; the headlights suffer with condensation; I had a coolant leak; I have steering wheel wobble; I think the air con compressor is failing; the Bluetooth module has failed; the radio crackles when you turn the heated rear screen on, and I had the infamous blocked engine bay drain hole problems, causing water leaks.

“So, in my view, if you buy a trouble-free 6 Series (unlikely), you’ll love the ownership experience. If you get one and have a few problems (likely), you’ll forgive them because you will still love the car. But if you buy one like mine (unfortunate), you’ll experience a roller-coaster of emotions; loving it, hating it and then looking out of the window and hating yourself for hating it!

“You probably won’t have a problem-free relationship, but any car that can invoke such strong emotions has got to be something special.”

The E63 6 Series Coupé’s looks have stood the test of time.

The petrol engines, while generally strong, good units, do have their inherent weaknesses, and some repairs can be expensive.

Check the operation of the hood on any potential Convertible purchase, and make sure that the vertical rear screen goes up and down properly.

The twin-turbo diesel engine that powers the 635d is the most economical option and is quick, too. It’s not faultless, though, and turbo failure is very expensive to sort out.

The E64 Convertible offers luxurious and sporting, opentopped motoring.

A well-sorted E63 6 Series Coupé is a great car to drive.

Top: Given its price point, this 6 Series was generally well-specified. When buying, take time to check that everything works properly. Above: Although there are four seats, leg room in the rear really is at a premium.

So don’t imagine that this car will waft four adults to the South of France in comfort.

Body corrosion, thanks to the widespread use of weight-saving aluminium and plastic, shouldn’t be a problem.

Check headlights for damage and condensation. The latter is a common problem and replacement lights aren’t cheap.

The assembled journalists reckoned the new 6 Series was a bit of a looker

“Always make sure that you check over any V8 very carefully. It must idle smoothly and not smoke”

“You’ll bag yourself a super cruiser that can double as a sports car when you want it to”