Porsche 928 Buying Guide

Overlooked for far too long, the 928 is now coming into its own as a fabulous grand tourer

Prices
• Project £5000 • Good £10,000-25,000 • Concours £25,000-70,000
• Most expensive at auction £222,589 (ex-Derek Bell Club Sport)

Practicality ★★★
Running costs ★★
Spares ★★★
DIY Friendly ★★
Investment ★★★
Desirability ★★★

Porsche gave itself a clean sheet of paper for the 928, and it came up with an engineering masterpiece. The all-aluminium engine was the first to be planned with Bosch’s K-Jetronic fuel-injection system in mind, the transaxle layout gave 50:50 weight distribution, and the ‘Weissach axle’ rear end resulted in a well-planted, predictable nature. Little wonder, then, that the 928 was voted 1978 Car of the Year.

Some road-testers, however, found the 928 hugely capable but difficult to warm to, while Porsche enthusiasts were a little slow to accept anything that wasn’t from the 356-911 bloodline. Marque big-wigs envisaged its rear-engined stalwart as being on borrowed time during the 1970s, but in the end it comfortably outlived the 928.

For a long time, you could secure this incredible GT for buttons. And even though prices are on the rise, there are few classics that rival the 928 in terms of value for money.

Your AutoClassics Porsche 928 inspection checklist

Engine

The big V8 can look somewhat intimidating when you first lift the bonnet, but the all-aluminium unit is robust and reliable if looked after. Make sure that you carefully sift through the car’s history to see what’s been replaced and what hasn’t. Budget for a cambelt swap at least every four years. It’s a vital area: from the S’s 4.7-litre engine onwards (so, 1980-on), the valves can come into contact with the pistons if it fails. The early 4.5-litre unit isn’t affected. It makes sense to change the water pump at the same time.

Check that the car doesn’t kick out any oily smoke when you first start it, as well as when it’s up to temperature and you rev it. If it does, suspect worn valve guides or even worn bores. Some GTS models suffered from porous cylinder liners, so check those in particular to ensure that they’re not burning oil. Poor running could be a knackered ECU (worst case) or it could just mean that the distributor and leads need renewing (best case).

Gearbox

While some purists prefer the manual gearbox, which is strong but not particularly sweet-shifting, the more plentiful automatic suits the 928’s nature down to the ground. The latter was a Mercedes unit that originally had three ratios – a fourth was added for the S2. It’s as solid as you’d expect, but a lack of pressure will lead to a slow or clunky shift. Check underneath to ensure that the torque converter or gearbox aren’t leaking.

Clutches last well, but pre-S2 manuals can suffer from problems with the synchromesh so listen for any untoward noises. It’s important to regularly check that the torque tube, which connects engine to gearbox, isn’t putting any untoward loads onto the flex plate at the flywheel. If it is, it will wear the crank thrust bearing and eventually damage the block.

Suspension and Brakes

A good 928 will feel secure and surefooted. If the suspension bushes are worn, you’ll both feel it and hear it during the test drive. If the car’s too ‘wallowy’, it could be worn dampers. Bushes are relatively cheap, dampers are not – especially the OE-spec units. Aftermarket alternatives are available, though.

It’s worth checking how old the tyres are, too, even if they look as if they’ve got plenty of tread left on them. Get underneath the car and make sure that the brakes and brake lines are in good condition, and look through the history for evidence of the fluid being changed.

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Bodywork

Anatole Lapine’s dramatic shape has aged well, in particular the uncluttered lines of the earliest cars. The bumpers were hidden behind polyurethane panels, while the doors, front wings and bonnet were made from aluminium. The rest of the structure was galvanised steel, so overall the 928 was protected against rust far better than some of its contemporaries.

In general, the bodywork should be standing up well, even 30 years later. Look for signs of mis-matched paint, though, especially on those bumpers, and poor panel gaps. Check underneath and in the wheelarches for corrosion, as well around the rear hatch. Areas that have received accident damage are prime candidates for rust, too.

Interior

If you’re used to a classic 911’s haphazard approach to ergonomics, the 928’s interior will be a delight. The build quality is impressive, too – as you’d expect – and from 1989 onwards the S4 gained a digital dashboard.

Early examples had the fabulous Pascha checked trim, which can come apart at the seams – reproduction material is available via specialists. For cars with full leather, patina is fine but tears are not.

Ensure that water isn’t getting in through the tailgate or sunroof by checking that the carpets aren’t wet. The electrics can play up on cars that aren’t used very often, so make sure that everything works – from warning lights and clock to headlights, windows and, if it’s fitted, air-conditioning. All can be expensive to fix.

History

  • 1977: Launched at Geneva Salon
  • 1980: S added with 300bhp, 4664cc V8
  • 1984: S2 introduced with 310bhp and new four-speed auto
  • 1985: S3 for North America only – 288bhp five-litre V8
  • 1987: S4 goes on sale with 320bhp variant of S3 engine
  • 1989: GT goes on sale
  • 1992: 5.4-litre GTS replaces S4 and GT
  • 1996: production ends

AutoClassics say…

Buy a 928 on condition rather than spec – it’s easy to end up with a money-pit if you don’t. In fact, the wisest money you spend will be on a pre-purchase evaluation. The Official Porsche Network, for example, offers a 111-point inspection. Also bear in mind that, while keen owners will be able to carry out simple jobs, you’ll benefit from having a friendly specialist on hand. And neither is the 928 the most economical option.

That said, this is a truly great car – reliable, fast, comfortable and stylish. It also has the advantage of being eminently affordable now that 911 prices have taken off. Really good early 928s are getting rare, but the S4 is a brilliant all-rounder and – if your budget allows – the GTS offers near-supercar performance.

Specifications

928
  Engine 4.5-litre
  Power 240bhp
  Top speed 138mph
  0-60mph 8sec
  Economy 15mpg

928S
  Engine 4.7-litre
  Power 300bhp
  Top speed 155mph
  0-60mph 6.2sec
  Economy 15mpg

S2
  Engine 4.7-litre
  Power 310bhp
  Top speed 159mph
  0-60mph 6.2sec
  Economy 18mpg

S4
  Engine 5.0-litre
  Power 316bhp
  Top speed 168mph
  0-60mph 6.3sec
  Economy 17mpg

S4
  Engine 5.4-litre
  Power 345bhp
  Top speed 168mph
  0-60mph 5.4sec
  Economy 15mpg

For Porsche 928s for sale, click here.

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