For many years, the E28 has been seen as the bargain BMW. But Chris Hope has discovered that prices for these torquey bombproof motors are on the rise

BMW’s second generation of 5-Series saloons have, in many ways, managed to stay under the radar of the classic car fans. Perhaps it’s because there’s something predictable, even mundane, about owning one of these bombproof machines.

But despite being seen as bargain motors, dwindling numbers are beginning to push prices up. Richard Hearn, from BMW specialist Fritz’s Bits is adamant that the price of your average M535i has risen ten-fold in the last decade. And as the pool of donor cars continues to shrink, prices for standard saloons will jump dramatically over the next five years.

So if you’ve ever fancied owning one of these reliable shark-nose saloons, now could be the time to buy. And with a wide selection of engines to choose from, you’re guaranteed top-quality motoring.

WHAT TO LOOK OUT FOR
Bodywork
With fabled German build-quality on its side, you shouldn’t need to worry about the steel on your 5-Series disappearing around you. But even with excellent rust-resistance, two decades of being driven and an average of 100,000 miles on the clock will mean there’s bound to be grot spots. The weak point for most E28 shells is the lower sections that surround the bottom of the A-pillars. Road grime collects above the jacking points and around the box section of the floor pans, causing these areas to corrode. In severe cases, the front edges of the sills will also be afflicted. It’s also worth checking around the hinges and check-straps of the front doors: it’s here that water collects in the door-seal retaining channels and then rots out the pillars. Unfortunately, it’s a screen out job to fix. Rear axle carrier mounts can be expensive to repair at £750-£1000 – the back-end of the suspension needs to be dropped for repairs.

However, if corrosion has spread to the double-skinned rear wheel arches, plus the rest of the rear structure around the differential, then you can expect a bill of at least £1500. Richard from Fritz’s Bits reckons he’s currently getting two E28s arriving a month with this problem. You’ve been warned.

Rubber seals for both the boot and tail-light clusters will deteriorate over time and provide a way in for water. A damp boot floor is a dead giveaway here, but a crusty rear panel is the first sign of neglect. The lower edge of the boot lid is also known to rot out. Check the front edges of the rear doors: the weatherproofing strips will harden and crack over time, providing a similar entry point for water. Good second-hand doors are getting expensive, though Fritz’s Bits can provide them at £120 each. Wings can rot at the front corners, but they’re bolt-on items and easy enough to replace. Both the suspension turrets and suspensions legs can also suffer.

There are a few minor points also worth considering: high-speed motoring will inevitably mean there’s a stone chip or ten. Chrome bumpers are becoming rare and expensive to replace, while refurbishing kerbed alloys can be costly. Many models were fitted with metric wheels, rather than the Imperial ones we’re all used to. This can make replacing your E28’s tyres expensive (up to £800, apparently). So source a set of 15in, 16in or 17in wheels instead.

Finally, if for any reason the E28 you’re looking at is fitted with sections of, or the complete, M535i body kit, exercise caution. In the past, these additional spoilers and skirts have been used to conceal rot.

Engine
One of the many attractions for prospective E28 5-Series owners, back in the mid-Eighties, was the choice of engines available: there was a selection of small sixes (M20s), big sixes (M30s), plus a 1.8-litre four-pot (M10) for the economy-minded motorist.

The main thing to bear in mind with any of these German engines is that while they have been built to last, they do require regular maintenance – anything less than a phone book thick service file is not a good sign. Engine oil needs changing every 6000 miles and coolant replaced every year to prevent aluminium cylinder heads from deteriorating and silting up the plumbing. So check for head gasket failure by removing the radiator filler cap and looking for mayo.

While out on the test drive, be sure to keep an eye on the temperature gauge needle – just to be on the safe side. After a spirited jaunt, the viscous fan should engage before disengaging once the engine has cooled. If the fan isn’t functioning, the powerplant will overheat.

Depending on the engine you’re inspecting, you’ll be looking at either a chain or belt-driven camshaft. The four-cylinder engine, along with the M30 big sixes, run timing chains that are a lot more durable than the 520i and 525e E28s, which have timing belts – they need changing every 30,000 miles. If the interval is coming up, ask about the condition of the water pump: it doesn’t need changing anywhere near as regularly, but it is easier to replace without the belt in situ.

If schedules have been faithfully followed over the past two decades, owners can expect 200,000 miles from their engines before they begin to falter. Other bits to watch out for include the metal fuel pipes, which can corrode over time and prove expensive to repair, and the air flow meter – a misfire or generally poor performance normally points to this component being worn.

If you’re lucky enough to find an M5, it’s worth noting that the engine has absolutely nothing in common with the M30 power plant in the M535i. The M88 engine is a 3.5-litre DOHC 24-valve monster, built to be both potent and durable at high speeds.
If you are looking at one of these, then be sure to ask when the timing chain was last changed. Intervals are every 100,000 miles. If missed, the chain will loosen and let go leaving you facing a bill for replacing 24 valves – did we mention that each valve costs £115? To make matters worse, Richard adds that BMW has recently begun to drop vital replacement chains and sprockets from its stock lists, so you might have a huge hunt on your hands for parts. Budget at least £3k-£4k for a rebuild.
Transmission

Manual five-speed gearboxes are as near bulletproof as you could hope. Both overdrive and dog leg versions – so-called for its rather redundant dog leg first gear (lots of wheel spin) – tend to resist synchromesh wear, and easily cope with starship mileage. Odd leaks are to be expected, but easily solved by replacing the selector shaft seals. Sloppy changes can be tightened up by investing in a fresh set of linkages.

The automatic ’boxes, particularly the four-speed ZF unit, aren’t quite as maintenance-free. The three-speeder isn’t too bad, but the ZF requires fluid and filter changes every 30,000 miles. If these have been observed then you can expect a 200,000-mile shelf life, if not the filter will clog and its bands will burn out without fluid.

Autos also have a separate gearbox oil cooler in the bottom of the radiator, meaning that if it’s not up to the task, both the engine and box will suffer. Owners can check the transmission dipstick for an idea of whether the system has been running hot: pale red fluid is a good sign, but if it’s burnt brown it will need replacing as soon as possible.

Richard reports that an increasingly common problem for the autos is stripped torque converter splines. If you’re going to try and fit an auto gearbox yourself, then be careful around the oil pump drive on the input shaft: if this breaks, the ’box is as good as scrap because the components are expensive – in many cases, more expensive than finding a replacement second-hand ’box.

Speaking of which, Fritz’s Bits provides a selection of second-hand gearboxes, the cheapest being the four-speed auto at roughly £294, ranging to £470 for the five-speed overdrive ’box for a 3.5-litre M30 engine. Note: when buying a replacement ’box for the 525e, that it’s unique to this model.

Running gear
Suspension bushes and shock absorbers are often overlooked by owners, despite such components being integral to maintaining the car’s road dynamics. E28s aren’t light saloons, so suspension wear is inevitable – but this isn’t an excuse to put up with sloppy handling.

Anti-roll bar bushes usually need replacing if you can sense a rattle from the front, while a clonk on take-off normally points towards the rear subframe bushes. Richard explains that when replacing worn bushes, they should be changed in axle sets. Strengthening only one side can produce some quite strange wear patterns on the tyres and, in the case of rear axle beam bushes (a very common weakspot), can cause steering shake. Unfortunately a specialist tool is required to remove these, so you’ll struggle to replace them yourself. Tackling the task without the correct tool can lead to expensive damage being caused to the rear cross member.

Changing dampers on the other hand is a simple enough task. It’s a job worth doing, even if they’re not leaking, a fresh set of dampers can transform the handling. You can get a full set of Bilsteins for £205 from Euro Car Parts (£95 for the front, £110 for the rear).
Moving on to the brakes, the main thing to check is the front callipers, which can seize. Steering judder under braking points to warped discs and/or a failed steering joint.
An anti-lock braking system was an option for most E28s and was standard on the majority of M30 engine models. The dashboard ABS light should illuminate once the engine has started and go out again almost immediately afterwards. No light could mean the bulb has either blown or been removed. If it stays illuminated, the system will need attention because a faulty ABS is an MoT test fail. Should the sensors need replacing, they can usually be found for £100 each: you’ll need four – one for each wheel. Slightly less expensive is the actual electronic control unit, usually £80.Earth wires from the battery to the ABS systems are often degenerated, leading to an incomplete earth, which can cause similar problems.

Electrics and trim
Just like the exterior, cabin trim has a fantastic reputation for durability. Fabric upholstery will inevitably wear with use. Once holes develop, replacement seat covers (or second-hand seats) will need to be sourced. Side bolsters in particular will go on the high milers, plus cloth trim on the door inserts is known to shrink when wet. Leather seats are a lot more hard-wearing, but can get expensive. Coveted Recaro examples are the most costly; expect to pay between £500 and £700.

Sunroofs don’t usually fail, but it’s not unknown for the handle on the manually-operated examples to snap if the roof mechanism is allowed to seize. The heating and ventilation system is usually okay, too – barring any clogs or a sticky heater valve.
The bigger concern here, though, is whether your E28 has picked up any electrical gremlins. The service interval (SI) system is the main problem: two NiCad batteries in the circuit retain the system’s memory. If these go flat and begin to leak on the circuit board, it won’t be long before things begin to play up. Replacement pre-facelift boards are getting hard to find – and costly at £280 through BMW – while post-face lift examples are not only more reliable, but cheaper to fix.

Most post-1986 518i, 520i and 525e cars were sold in ‘Lux’ spec. This includes sunroof, front electric windows, central locking and hardier velour trim. Regardless of trim level, a general check of the electrics is advisable as motors can (and do) fail.

Worthwhile upgrades
One of the best ways to improve any Eighties BMW is to replace the standard exhaust manifold. Fritz Bits’ replacement manifold and system offers quite a kick – an extra 20bhp, plus improved torque on the M30 engines. To capitalise on these gains, Fritz’s offers a selection of ECU chips for the fuel-injected engines. These are intened to remove any weak points from the rev range and provide better fuel economy. E28 manifolds cost £529, while the full exhaust system is £1116.

Better stoppers make sense for the big sixes, where underbraking can be an issue. Fritiz’s will uprate the 5-Series anchors to those from either the later E34 540 or the 7-Series E32 750. Discs, callipers, cylinders and braided brake lines will cost around £750 or £950 fitted.

Finally, a front strut brace will prove to be a good buy at £170: it not only tightens up the handling, but is a welcome safety precaution for nose-on collisions.