Buying Guide How to buy the best Porsche 928… The 928 remained in production for 18 years and time has confirmed it as one of the world’s great GTs. Values bottomed some years ago and have continued to steadily increase. Expect a car that feels firm and planted on the road, with relatively heavy steering, especially on earlier iterations. Manual shifts are fairly notchy, better on the later GT and GTS, and the throttle pedal has a long travel.
Though it’s unlikely you’ll find a service book fully stamped by Porsche main dealers, you’ll want to see documentary evidence of consistent care with fluid changes at the right intervals – and MoTs that tie up with the odometer. Bosch has stopped making a lot of the electrical parts – MAF sensors, for example – but specialists have stepped in to fill the gap and spares support is pretty good. John Speake of JDS Porsche (01233 709915) for example, repairs them, plus the fuel injection ECUs, for £320 apiece, and there’s a wealth of knowledge out there on the internet to help you.
Porsche purists were horriied when the futuristic 928 appeared over 40 years ago. Big, water-cooled and – shock, horror – front-engined, it was a radical departure from the marquedeining 911. Rear end featured recessed lights until 1987.
On a car this complex, when you find one you really fancy, an expert opinion is vital and worth paying for. Porsche Club GB (porscheclubgb.com) is a good starting point for contacts. We spoke to 928 Register Organiser David Hemmings, to Adrian Clark who is PCGB’s technical advisor on the model and has raced them since 2007, and to Paul Lacey (paullacey.org.uk) who offers specialist help including engine rebuilds.
There’s a bewildering choice of permutations, from early 4.5-litre 240bhp cars to the final 5.4. For most enthusiasts it’s a choice of the clean styling of the recessed tail-light S1 and S2, or the added sophistication of later cars. Earliest cars have ‘telephone-dial’ wheels, very early ones lack spoilers and side strips. S4s offer more luxury and speed while the GTS is the most hardcore and most expensive to ix, having unique brakes and engine. Most are autos, but that suits the car’s character. Here’s a summary.
1977-1982: 928 launched with new water-cooled, 4474cc V8 K-Jetronic engine giving 240bhp and 140+mph top speed. Five-speed manual or three-speed automatic transmissions.
1979-1984: 928S gets 4664cc L-Jetronic engine, plus small front and rear rubber spoilers and side-protection strips; 300bhp with 152mph top speed.
1984-1985: S2 has 310bhp LH-injected engine; auto gearbox is now a four-speed.
1985: US-only cars receive new four-cam 5.0-litre V8, four-valve cylinder heads and unofficial ‘S3’ title.
1987-1992: S4 has smoother front end, wraparound tail-lights and big rear spoiler. UK-only SE (manual only Sports Equipment, 42 made) is equivalent to rest-of- the-world Club Sport, (left-hand drive, 71 made).
4957cc 32v V8 with LE injection gives 320bhp. Digital dash and auto ’box standard for ’1989-on S4.
1989-1992: manual-only GT introduced with stiffer suspension, 16in wheels and 330bhp, twin tailpipes.
1992-1995: GTS has 5399cc V8, 340bhp, Cup 17in alloys, colour-coded rear spoiler, Turbo external mirrors, full width rear light panel.
Engine / transmission The V8 (two-cam until S4) is largely bulletproof, going up to 200k miles between rebuilds if looked after, but resist a smoky engine. A slight vibration at idle suggests worn engine mountings (£250 each plus labour). Cambelt interval is 60,000 miles or four years, and it’s wise to renew the water pump at the same time; make sure you see a bill for this. The original 4.5 (up to 1984 non-S) is a non-interference engine, but all the others will bend the valves if the timing belt breaks, though the pistons usually survive. Engine rebuilds cost upwards of £3500, or the same for a secondhand engine.
Pipe failure to the oil cooler and steering rack isn’t unknown so look for oily front brakes and backs of wheels. Check for leaks from the power steering reservoir (big bottle with ZF on the cap).
The V8 powering Porsche’s big GT grew from 4474 to 5399cc during the 928’s 18-year lifetime. Cambelt interval is 60,000 miles.
Check the condition of the fuel pipes generally, because engine fires are not unknown. On 32v cars (1987 on) check the condition of the fuel hose that runs in front of the oil filler neck – if incorrectly fitted it eventually wears through, resulting in a fine spray of fuel over the engine, which has destroyed more than one car. A braided replacement is good to see here. If it’s a GTS, don’t be concerned if the engine has been fixed under warranty; they had oil-burning issues, but check if the engine has been replaced and ask about oil consumption – if it’s a burner, walk away. You can’t see oil haze as the cats stop it.
Crankshafts on automatics can be destroyed by incorrect flex plate tension. This affects S4s more than S2s but ask if it’s been checked. If the owner doesn’t know, have it checked by a specialist or walk away. Clutches are expensive – reckon on £1000 just for parts, not all of which are available for early cars.
Listen for bearing noise varying with pedal pressure, and on later, torquier cars, clutch slip on hard acceleration. Actuation is hydraulic, so if it’s failed completely you won’t be able to engage any gears. If there’s drone from the torque tube bearings, best walk away or negotiate a big discount because it’s another £1000 job that’s not do-able at home.
Electrics of 928s have a propensity to deteriorate if they’re allowed to stand or get damp, though by modern standards the wiring is fairly simple and easy to trace. John Speake of JDS says, ‘Up to S2 they are relatively straightforward though the fuse boxes are quite daunting with 40-odd fuses and lots of relays. Later cars have extras too, such as memory seats in S4s, and electro-hydraulic differentials.’
Plug-in diagnostics arrived only in 1988, and on these cars it’s worth paying someone to check for fault codes (refurbished Hammer testers are available from jdsporsche.com). Other than that, check that when you switch on, all the instruments and warnings light up, and that the ABS light goes out when the engine starts.
ABS warnings are common with the digital dash that arrived in 1989; the problem is likely a wheel sensor (about a £100 ix). But if the PSD (electro-hydraulic LSD) warning lights too, there might be a problem with the high-pressure hydraulic pump, which will easily cost £1000 to put right. The good news is that fuel pumps cost only £100. Later cars have two, but can be converted back to the original single system, doing away with the in-tank lift pump.
Now check secondary features: central locking, boot release, electric windows/mirrors/seats and sunroof motor. Beware of extra underbonnet alarms – poorly executed alarm wiring leads to breakdowns or worse. As Speake says, ‘An unskilled person getting into the electrics is the worst thing that can happen to a 928.’
Bodywork Galvanised and part-aluminium, yes, but not totally rotproof. Look for paint bubbles in the front wings, door skins and around the rear side windows; the aluminium bonnet can corrode too. Accident repairs are a breeding ground. Get underneath to check the rear of the sills, obscured by plastic covers on later cars. All panel gaps should be consistent. Is the sunroof motor working? Non-sunroof cars are sought after because they don’t leak.
Wheels Ideally you want the originals; many cars have later or aftermarket wheels, sometimes with spacers at the rear. Are the originals available with the car? And is it on the right tyres? As well as correct sizing (the internet is your friend here), are the tyres N-rated? If not, previous owners might have cut other corners too.
Interior Check for wet carpets, indicating tailgate/ sunroof leaks; in the rear it’s often the window seal, obscured by trim, rather than the hatch rubber, but that’s not a dealbreaker. However, check the roof lining and door cards are not warped from damp. Part-leather interiors were standard, but early cars had the option of cloth including the psychedelic Pasha pattern (up to 1984) that’s now available again from Germany (werk924.com). Seat leather generally wears well, although edge beading isn’t as robust. If the dash is leather, has it pulled away from the vents?
Out back, is the luggage cover still present? Most cars had aircon; if it works it’s a bonus. If not it’s usually a case of more than regassing.
Leather seats usually wear well. This is a fairly restrained version of a 928 interior. Early cars had the option of cloth in psychedelic Pasha pattern.
What to pay
£4000 got you a driver-quality runner not long ago. These days that’s project car money
Fair ‘driver-quality’ S2s fetch £8k, but they can end up costing much more
Track day cars start at around £12k
Good restored early cars go for £15k £15-18k: cheaper, likely repainted S4s
Starting point for nice S4s is £25-30k
S4s with lowish mileage and FSH start at £35k
GTs and GTSs start at £40k, and will probably be in left-hand drive
Perfect low-mileage GTSs will fetch £70k+
‘There’s a bewildering choice of permutations. For most enthusiasts it’s a choice of the clean styling of the S1 and S2, or the added sophistication of later cars’
‘The V8 is largely bulletproof, going up to 200,000 miles between rebuilds if looked after’
How buying a Porsche 928 needn’t be risky
Owning a Porsche 928
Graham Martin and Jay Winter jointly own the car in the photos – it’s one of four 928s they’ve owned between them, and Martin still has an earlier S2. ‘We both had an epiphany when at 18 a wealthy young friend of Jay’s turned up with a new 1980 Porsche 928S in Guards Red,’ says Graham. ‘Its Gerry Anderson UFO styling blew us away – it was light years ahead of our daily drivers back then, a Triumph Vitesse and an Escort Mexico. The interior was ergonomically perfect and the rumble from Porsche’s V8 put the hairs on our necks on end.’
‘Scroll on four decades and a collection of interesting cars behind us, we co-own this three-owner, 38,000-mile 1981 non- sunroof 928S auto. It is a rare car having been specified with a full leather interior including magnolia seats and fawn carpets to raise the mood – many 928 interiors are all-black. It has the upgraded hi-fi system with eight speakers. Jay sourced an OEM radio/cassette rather than the archetypal Blaupunkt.’ And it’s now for sale! Visit the928.com.
Marc Chenery paid £4000 privately in 2014 for his 1985 S2, which pretty much represents the bottom of the market. He drove it home 150 miles from Cheshire, ‘I bought it for my birthday. I’d had big V8s before – Interceptors and Rover P5Bs – and as an architect I’d always liked 928s for their timeless design, so I wanted the original recessed-taillight car.
‘The temperature gauge didn’t work, but the previous owner had wired in a remote dial. I had it serviced for £250 – a cambelt change is about £500 – then drove it daily for 18 months in all weather, including four days in the snow. It’s been faultless, apart from the rear hatch sometimes springing open on bumpy roads. All that needed was a new plunger, spring and plastic sleeve for £12, mail order.
‘It gets hot inside – the aircon doesn’t work, of course – but you just open a window. I’ve even had four people in it. I only stopped using it because someone gave me an X5 which is more suitable for work, so now I’ve pulled out the interior to have the worn seat bolsters recovered, and the rest re- Connolised. I’m also going to it some new glassfibre boot side trims that I found in the US.
‘I’m 6ft 5in and 21 stone with a 54in chest and it its me perfectly. As I slide down into the seat it’s like a bespoke suit. I now know how Dan Gurney felt in a GT40, but I don’t quite need a roof bubble – there’s a finger clearance between the top of my head and the sunroof.’
Adrian Clark has owned 928s since 1989. He’s raced the big Porsche GTs since 2007 and his collection currently includes two race cars (one with an engine bored out to 6.4 litres), three SEs, a GTS and a 500bhp supercharged GT.
‘My first 928 was a 928S manual I bought in 1989. Great car except the cambelt went after a week, luckily with no major damage because it happened at low speed. Since then I‘ve owned many, though my passion since 2007 has been racing my two 928 GTSs. Both have been racing since the mid-Nineties and have been developed over the years to be competitive and beat more modern Ferraris and Astons.
‘They can be very competitive race cars, handling being their biggest advantage along with the powerful engine and torque. You need a dry-sump upgrade to avoid engine failures though, and additional gearbox cooling is important. For 2018 I hope to be campaigning again in the BARC Intermarque Championship and CSCC Future Classics series.
1990 Porsche 928 S4 Auto £14,250
Featured in the BBC series Shetland, for which it was specially painted yellow. Approx. 111,000 miles, recently had its belts changed and is ready to enjoy.
Automatic gearbox. Fully loaded. Long MoT. Bills with car, plus original handbook, service history book and complete original toolkit. Recent jobs include new cambelt and water pump, reconditioned radiator, and tank cradle assembly replacement.