Buying an older BMW – especially an M car – is all the rage now. With the values of many models growing dramatically over recent years, these cars can now offer financial security in addition to immense driving pleasure, so what’s not to like?
Well, some M cars are more popular than others, and a quick trawl through the offerings on Pistonheads will reveal what’s hot, and what’s not! Of course, the smart money is always searching-out the next ‘big thing’ and, in M5 circles, the E39 has long been touted as the one to watch. For whatever reason, though, values have stubbornly refused make any significant headway and, although prices undoubtedly bottomed-out two or three years ago, the big push has yet to arrive.
But that’s a good thing for most enthusiasts living in the real world, because it means that this fine car remains affordable for the time being. This is great news because, as an allround performance package, the E39 M5 certainly takes some beating. If you’re in the market for a well-specified, comfortable five-seater offering a refined, understated image combined with stonking, super-saloon performance, then you’d be hard-pressed to find better value for money than this M5.
As an all-round performance package, the E39 M5 certainly takes some beating
Based on the excellent E39 5 Series, this car’s ability to cover the miles with speed and comfort is almost legendary; its lazy power delivery and well-insulated interior combine to produce the consummate sporting mile-muncher. At the heart of the car’s abilities, of course, is the wonderful S62 engine; a free-revving, 4,941cc V8 delivering nearly 400hp.
Coupled to the rear wheels via a six-speed, manual ZF gearbox, this motor was a higher-capacity, tuned version of the M62 from the 540i, and could push the M5 to 60mph in under five seconds. It was also the first BMW engine to feature a double Vanos (variable valve timing) system.
Launched in 1998, this third generation M5 took the model to a new performance level, although some enthusiasts missed the previous model’s excitingly revvy, straight-six engine.
The car ran on 23mm lower suspension than the 540i, and featured uprated dampers and thicker anti-roll bars. Beyond that, though, the only obviously visible difference between the M5 and lesser models were its smart, 18in alloys, ‘M5’ badging and quad exhaust tail pipes. It was all very subtle.
Production ran until 2003, with a largely cosmetic update occurring in 2001. The total E39 M5 production figure is listed as 20,482, although it’s thought that only about 2,500 of those found their way to the UK, in right-hand drive form.
Fast-forward 14 years, and a decent number of this third generation M5 still survive, although the recorded mileages of most are typically well north of 100,000. The buying public’s on-going fixation with vehicle mileage, means that low-mileage examples – and there are still a few around – demand high prices (refer to the What to pay? panel). However, the good news is that knowledgeable buyers certainly shouldn’t be scared-off by high mileages. The model’s generally high level of build quality, combined with the large capacity and relatively unstressed nature of the engine, mean that E39 M5s are well capable of coping with heavy use, assuming maintenance levels are as they should be.
Sadly, though, it’s sub-standard servicing and maintenance that’s to blame for many of the problems now being encountered. Once these cars fell into the hands of their fourth, fifth and sixth owners, the amount being spent on looking after them tumbled. So, with the cheapest examples being available for under £5,000 a few years ago, they were often bought by ‘bar-room braggers’ with no real interest in – or sympathy for – the mechanical aspects of the car; they simply wanted a 400hp super-saloon to thrash, with little or no maintenance!
But the damage certainly wasn’t all done in recent years, as many of the original owners were to blame for inappropriate use, the full effects of which are with us now. The assumption that, just because a new car is being fully maintained by BMW, it can be driven however the owner wishes, is a flawed one, especially in the case of an M car. The failure to allow the engine to warm up adequately before putting it under any significant load, is a recipe for mechanical disaster. Sadly though, it’s never the perpetrators of such insensitivity who pay the price for their short-sighted indulgence, as they’re always long gone before any trouble strikes.
The first point to make is that most people buying an E39 M5 nowadays will be acquiring an unknown quantity. Only a few examples will have full service and maintenance/repair records, so new owners must face up to the fact that pot luck will be involved. Until a ‘new’ car is able to be properly inspected by a knowledgeable and experienced professional, then there’s no telling what gremlins might be lurking within the machine!
Thanks to relatively affordable purchase prices, it’s all too easy to forget that the E39 M5 is a sophisticated, high-performance saloon. Cars of this complexity can’t be maintained on a shoestring, despite the fact that you can buy them for the same price as a secondhand Ford Mondeo or Vauxhall Insignia. Cutting servicing corners is a totally false economy that will rapidly exacerbate any existing problems or mechanical weaknesses.
Probably the most serious mechanical issue to be aware of is con rod shell bearing wear, which is potentially catastrophic. While there isn’t an inherent weakness within the engine, shortfalls in terms of oil changes, lubricant quality and/or unsympathetic engine use, will combine to greatly accelerate wear rates and cause trouble.
The official, BMW-recommended service interval might also have something to do with the problem that now afflicts many cars. Oil changes are triggered based on the car’s on-board, condition-monitoring system which, typically, will set the interval at about 15,000 miles. This is a potential problem, as far as experienced M-car specialist James Redish (Redish Motorsports, tel: 01179 781889) is concerned.
“I think 15,000 miles is far too long to run a complex, high-performance engine like this V8 on the same oil,” he warns. “Such an interval may have been acceptable when the engine was brand new but, well over a decade later and with six-figure mileages covered, following that recommendation just isn’t appropriate any more. My advice is that the oil should be changed at least every 7,000 miles (or annually) and, ideally, more frequently than that. It’s also essential to stick to the appropriate grade; Castrol Edge 10W60 synthetic oil was developed for use in this engine, so that’s what I continue to use and recommend.”
It’s the con rod shell bearings that are most vulnerable to the effects of contaminated or inappropriate grade oil, as well as poor driving style. As they start to wear, the first consequence will be bottom-end knocking under acceleration, caused by the gap between the crankshaft journal and one or more of the shell bearings becoming wider, allowing mechanical play.
Allow the condition to persist, and bits will start chipping off the bearings, further contaminating the oil and accelerating wear rates here and elsewhere around the engine. Heat generation will increase, and the shell bearing will then start to spin in its mounting, at which point catastrophe will be only moments away. If the bearing destroys itself, the con rod is likely to snap and punch its way out through the side of the engine block.
Obviously, it’s impossible to predict shell bearing wear rates, which is why many owners now have them changed as a precautionary measure. While this is likely to cost about £2,000 at a good, independent specialist, that’s better than having to pay the £8,000+ required for a new block and engine rebuild, should things go pop.
A MATTER OF TIMING
Wear inside the Vanos units is another very common cause of trouble which, in this case, can create an unpleasant, almost diesel-like rattle from under the bonnet. It’s the bearings on the helical gears inside the Vanos units that are the wear points. They are lubricated by engine oil, although they don’t have a direct feed, which might be part of the trouble.
However, this Vanos problem doesn’t actually create a performance issue, or a mechanical danger for the engine, it just produces a horrible noise! Putting it right tends to be an expensive business with no real guarantee of complete success, so many owners just live with the rattle.
The Vanos units can also leak oil down the front of the engine, due to worn O-rings, although these are relatively easy to replace (without affecting the valve timing). Another issue relates to the Vanos control solenoids. These are soldered into place on a circuit board, but their joints can develop hairline cracks that will disable the solenoid and cause all sorts of drivability issues. So it’s worth checking for this problem carefully, as the solenoids themselves are very expensive to replace.
A set of four is needed for each Vanos unit, and each set costs about £1,000; a high price to pay if the problem is merely one defective, soldered joint!
LACK OF TENSION
Another under-bonnet rattle can be caused by wear in the timing chain tensioners. This tends to be most noticeable with the engine at idle, and is caused by the chain being slack enough to slap against its plastic housing. The plastic guides on the tensioners are what harden and eventually snap off , but replacing them is an unfortunately big job. It requires the removal of the radiator, the Vanos units, the camshaft sprockets (engine timing is lost) and the timing chain case. This will cost about £2,600 (including a Vanos unit re-seal).
Oil leaks are something else to check for during a pre-purchase inspection. There are a couple of characteristic ones, including the power steering pump and the rocker cover gaskets. The rocker covers are made from cast aluminium and so can suffer with oxidisation as they age, which builds up and leads to leaks around the gaskets.
Rubber hoses (air, fuel and oil breathers) can also cause problems as the mileage builds. A couple are easily accessible on top of the engine, but most are buried under the inlet manifold. Hardened, split rubber will induce air leaks that, in turn, will trigger rough-running issues. It’s a good idea to swap all of these rubber pipes in one go, as part of an engine re-fresh.
SPRINGS AND THINGS
The propshaft can be another potential source of unwanted noise on an aging E39 M5, producing an odd ‘tinging’ sound as the power is taken up in both first and reverse gears. Sometimes this is due to play in the CV joint at the rear of the shaft but, more typically, it’s caused by wear in the UJ. The latter is integral, so new ones are only available when specifying a replacement propshaft (£960 from BMW).
Differential oil leaks are quite common, and it’s the input seals that are the characteristic problem. Oil loss from these can cause what looks like a catastrophic leak under the car, with spray thrown everywhere. In reality, though, the diff s never lose enough oil to cause a problem, it’s simply more of an annoyance than anything else.
Any cars still running on their original suspension are likely to be suffering with worn-out dampers by now. It’s a common, age-related problem but, because it’s such a gradual decline, most owners never notice the deterioration in handling. In fact, the shock absorbers can lose performance (especially rebound) in as few as 50,000 miles, but it’s all but impossible to check for this without stripping and removing components.
Replacements from BMW are perfectly good, although lots of owners take the opportunity to switch to Bilstein dampers (those specified for the 540i), which are a good option – some consider them an actual improvement – and more affordable than the standard equipment. Staying underneath the car, weak or seized handbrake mechanisms are another common occurrence, often resulting in MoT test failure. Unfortunately, getting a failed system back up to test standard is likely to require the replacement of everything, which involves quite a lot of work.
When on your test drive, be alert for vibration when braking, which is often caused by wear in the rubber, front control arm bushes. If this has been ignored and reached an advanced stage, then it’ll be quite apparent (felt through the steering wheel) during normal driving. Polyurethane replacements are not recommended for this application.
By and large, the interior is standard E39 5 Series, so it’s well screwed-together and durable. Pixel loss can spoil the LED display panels (driver information between the dashboard dials, and radio information in the centre console). Replacement panels are available, but fitting involves careful soldering, so is probably best left to an experienced professional.
Buy the wrong car and you could find yourself faced with a series of wallet-bashing repair bills
Incidentally, with regard to dodgy digital read-outs, if an MoT tester isn’t able to read the mileage during the test, then they’re obliged to enter a mileage figure of ‘Zero’, which isn’t ideal. Worse still, the tester may guess at the figure without reference to the previous year’s total, and get it completely wrong. Such errors can be appealed after the test, but this can be a slow and frustrating process.
Other electrical systems on this M5 are generally reliable and well designed. However, take a moment to check that the heater fan works correctly. If you find it’s impossible to alter its speed, then there’s likely to be an issue with the heater resistor pack. This unit – affectionately known as the hedgehog, due to its ‘spikey’ appearance – is found in the side of the heater box and accessed via the driver’s footwell.
Age-related faults with it can also result in the heater fan running continuously at very low speed, even when the ignition is switched off. This can be the cause of a mysteriously flattened battery. Genuine replacement resistor packs from BMW cost just over £80, and plug straight in.
The air conditioning is a reasonable system on this car, all things considered. However, one thing to watch out for concerns the electric pusher fan that’s mounted in front of the system’s condenser radiator, right at the front of the car, behind the kidney grilles. Living its life in a relatively exposed position, this unit can eventually succumb to water ingress and debris build-up.
So discovering a fan motor that’s running slowly – or is seized altogether – isn’t uncommon. As well as reducing the efficiency of the air con system, problems with this fan can also have a bearing on overall engine cooling – this condenser unit sits immediately in front of the engine’s main coolant radiator. Therefore, cars that are seen to be running slightly too hot may be suffering in this way.
Another issue relating to this fan is that the plastic guard that protects the blades distorts with age; so much so, that it’ll often come into contact with the spinning fan, with understandably noisy results.
The final area we need to talk about is body corrosion. The age of the E39 M5 inevitably means that rust is becoming an increasing problem, so it’s something that all buyers should bear in mind. While the car isn’t a particularly bad sufferer, there are some key areas to check before parting with any cash.
The car is fitted with four, solid rubber jacking blocks, one at the front and rear ends of each sill. Unfortunately, the bodywork around these blocks corrodes dramatically (especially at the rear). However, these areas are hidden from general view by plastic covers fitted to the undersides of the sills, so it’s not until these are removed (or the car is raised for a proper inspection on a vehicle lift), that the full extent of any problem can be properly assessed. This sort of corrosion can quite quickly become a structural issue if left unchecked, resulting in MoT test failure.
Launched in 1998, this third generation M5 took the model to a new performance level
Regrettably, putting this right properly is a massive job. There are no repair sections available so, unless you’re able to organise decent, hand-made and shaped pieces to replace the rusty areas that’ll need to be cut out, the only option is to buy new sill sections from BMW. The trouble is, these aren’t the simple sill panels you might imagine; they cost nearly £1,000 each and incorporate the A, B and C pillars! Fitting them essentially involves replacing the whole side of the car, with all the work that that entails (removal of the fuel tank, rear axle and interior, etc).
Other favourite E39 corrosion points include the boot lid (just above the rear bumper and around the number plate lights), around the petrol filler cap (along the bottom edge of the cavity, just inside the flap), the lower front wings (where they meet the front of the sills and the return of the front bumper panel). It’s also worth checking inside the boot, as water can find its way in around aged seals, and there’s quite a lot of sensitive electrical equipment in there, including the sat nav controller.
The E39 M5 is an interesting car that draws many a potential buyer because of its wolf-in-sheep’s-clothing-type appeal. What’s more, as they continue to remain pretty affordable, and there’s little else to touch its combination of grace with pace, this understated M5 is an understandably attractive proposition.
But, on the flipside – as you should be aware by now – it’s also a vehicle that can represent something of a gamble. Buy the wrong car and you could find yourself faced with a series of wallet-bashing repair bills. As I mentioned earlier, it’s not a car that’s going to be cheap to run or maintain; potential owners should be under no illusions about that.
However, those looking to buy should also be assured that the E39 is a fundamentally good vehicle and that, in this M5 guise, it has the power to cosset, to thrill, to scare and to delight. It’s a car of great and wide-ranging abilities that will reward thoughtful and considerate owners with good times a’plenty.
The secret, of course, is to go into any E39 M5 purchase with your eyes wide open. Do your research, realise what you’re buying and pick a car with a strong service record. If possible, buy from a genuine enthusiast; somebody who appreciates what the car’s all about, and who will have given it the care and attention it deserves. Find out about what remedial work’s been done on the car and, equally importantly, who by. If repairs haven’t been done properly then, in some respects, it might almost be better if they hadn’t been done at all.
Finally, as the proud new owner of an E39 M5, you’ll need to be prepared to spend money on the car and, in most cases, quite a lot of money. So it’s important to have £5,000-£6,000 in reserve to fund the initial refurb/repair work that’s likely to be needed. But rest assured that, once you’ve got it sorted, this is an M5 that’ll run and run, and deliver smile-inducing pleasure every time you drive it.
WITH THANKS I’m very grateful to James and Luke at Redish Motorsports, for their expert buying tips, to owner James Pingstone, who kindly allowed us access to his car and to London-based Hexagon Classics (tel: 02083 485151) for providing the excellent images of the blue car featured here.
WHAT TO PAY?
Gone are the days when you could find an E39 M5 selling for under £5,000; in pure value terms, this model bottomed-out several years ago, and now – at long last – it’s on the up. Today, the entry level sits at around the £8,000 mark for an early, pre-facelift car, but you really will be taking a bit of a gamble at this end of the market. You’ll need to budget £12,000- £14,000 to secure yourself a car that’s in reasonable condition, and a vehicle that’s been looked after and had some of the characteristic failings properly dealt with (hopefully).
The market is more buoyant for low-mileage, pristine examples, for which you can pay anything up to £30,000, from an established dealer. However, such cars can prove something of a double-edged sword. The low mileage and high price tag will create quite a disincentive, as far as regular road use is concerned. What’s more, the relative lack of use, combined with the ever growing age of the vehicle, will mean that it’ll likely be suffering will all sorts of niggles.
So it’s far better, in many respects, to buy yourself a well-used and properly cared for example, have some additional money ready to spend, then start getting some real pleasure from the car.
OWNER’S VIEW JAMES PINGSTONE
“I bought my E39 M5 early in 2014 and I’m the third owner; I knew the previous owner and he’d had the car for about four years. The original owner was a helicopter pilot, so I’m fairly sure that the vehicle has been in mechanically sympathetic hands for all its life.
“The car remains standard apart from the Bilstein damper conversion. I realised pretty early on that suspension was quite tired – there was far too much body roll – and the Bilsteins really have made a fantastic difference to the handling.
“I’ve covered about 16,000 miles so far, and I really can say that it’s exceeded my expectations. There’s so much usable power and torque but, at the same time, it’s a subtle M car. It has all the attributes you’d expect, but remains an easy and comfortable car to drive.
“I also own an E34 M5, and the contrast between the two is an interesting one. The 3.8-litre, straight-six howler in the earlier car is a great engine, and very different from the V8 in this model. The progress made by the BMW designers with the E39 is very evident; it’s certainly at a different level compared to the previous version. The power is always right there, you never have to work for it as you sometimes do in the E34. They are very different machines, but the E39 is certainly the faster and easier car to drive quickly. “My car is a good, honest example. I know it’s not perfect and I have a list of jobs still to be done. But I’m taking my time and am really enjoying the whole process. It’s a delight to own!”
Understated, stylish and a consummate performer; the E39 M5 can offer enthusiastic drivers the complete package. (Pic: Hexagon Classics).
The interior is pure E39, so it’s well made and generally durable. Later, facelifted cars got grey-faced dials. Watch for age-related pixel losses on the info and radio screen; things can become difficult to read.
Uprated suspension, thicker antiroll bars and quad exhausts are just about all that separate the E39 M5 from the 540i.
Left: Body corrosion is becoming a problem on all E39s. This area near the boot lid latch is common; unsightly but not structural. Middle: Don’t forget to check for corrosion behind the fuel filler flap. The bottom edge of the compartment traps water, and there’s only one result. Right: This is the plastic blade shield that distorts and can interfere noisily with the air conditioning condenser’s cooling fan, immediately behind the kidney grilles.
Four-doors and a large boot endow the E39 M5 with practical, family-friendly credentials. (Pic: Hexagon Classics)
Here’s the sort of corrosion often found around the jacking points. This was found on an otherwise immaculate-looking E39 M5!
Anti-chip paint on lower sill section / Rusted hole in underside of sill / Rubber jacking block / Vehicle hoist pad
Above: Worn con rod shell bearings like this are something to be guarded against. Promoted by poor oil choice, inappropriate use and cost-cutting maintenance, they can spell disaster for the engine.
Right: The 5.0-litre V8 at the heart of this third-generation M5 is a great engine. Some will run cooler than expected, with the needle sitting well below the half-way point on the gauge. A faulty thermostat is typically the cause.
The BMW E39 M5 doesn’t represent a money-making prospect as things stand, but is certainly a model worthy of serious restorative input whenever possible. (Pic: Hexagon Classics).
Replica bumpers are typically available for about half the price of the genuine article from BMW; it seems like a good deal, until you notice that they don’t quite align with the wheel arch!
Effortless and fun the drive, the V8-powererd E39 M5 took performance to a new level when compared to its straight-six-equipped E34 predecessor.
DATA FILE E39 M5
ENGINE: S62B50, V8
POWER (HP/RPM): 394 at 6,600
TORQUE (LB/FT): 369 aat 3,800
0-62MPH (SECS): 4.8
TOP SPEED (MPH): 155 (limited)
WEIGHT (KG): 1,720