Buying guide Porsche 911 Cabriolet 964

The 964 has seen huge growth in popularity in recent years, and yet the 964 Cabriolet remains one of the most affordable entry points to ownership of an air-cooled Porsche...

Words Dan Furr

Photography Dan Sherwood

BUYING GUIDE

Bag yourself a tidy Porsche 911 Cabriolet 964.

Launched in November 1988, the 964 marked a sea-change in the 911’s development. Porsche CEO, Peter Schutz, and the company's chief engineer, Helmuth Bott, aimed to make the new model the most advanced sports car to wear the 911 badge. Indeed, many of the 964’s key features were inherited from the earlier 959, bringing supercar technology to a much wider audience.

Despite Porsche claims the 964 was eighty-seven percent new when compared to the outgoing Carrera 3.2, changes to the iconic 911 silhouette were prohibited. Nevertheless, the 964's polyurethane bumpers, aerodynamic rain gutters and flat undertray were all new components taking clear cues from the 959.

The 964’s drag coefficient was improved to 0.32 over the Carrera 3.2’s 0.39. Additionally, devoid of any superfluous addenda, the newer 911’s passage through air was helped by a retractable rear spoiler, which automatically extended at 50mph, eliminating the risk of lift at high speed.

The first 964 to land was the Carrera 4, so-called because of its 959-derived four-wheel drive system. Porsche purists may have howled into their Black Tower, but the manufacturer was keen to push the 911 envelope. Tellingly, despite sixty-nine percent of the Carrera 4’s power being sent to its back end, many of the outgoing 911’s driving characteristics were retained.

The most powerful normally aspirated 911 in the model’s then twenty-six year history, the Carrera 4’s flat-six M64/01 engine boasted 3.6 litres of displacement.

Power was up to 250bhp with 228lb-ft torque delivered at 4,800rpm, enabling a sprint to 60mph from rest in just 5.5 seconds, romping on to a top speed of 163mph. If the four-wheel drive system had caused consternation, the performance of this new 911 for a new era certainly didn’t. It wasn’t just the model’s engine that was substantially revised, though. Underneath the familiar lines and stovepipe front wings lay a coil-spring suspension system (the long-used torsion bar setup finally junked), as well as ABS and power steering as standard equipment. The rear-mounted powerplant remained unhindered by the new safety systems — speed freaks could still wag the tail, even if it did require more provocation than ever before.

The 964 was launched as a coupé, although it didn’t take long for Cabriolet and Targa variants to materialise. Each car represented a thoroughly rejuvenated 911, with twin front airbags (for cars sold Stateside), a redesigned climate control system, a three-way catalyst and an impressive ten-year anti-corrosion warranty.

With the new decade came a two-wheel drive 964 in the form of the hugely popular Carrera 2. It shared the fourby’s engine, but was the first Tiptronic-shifting 911 thanks to the option of a four-speed, electrohydraulic semi-automatic gearbox.

Despite spending many years regarded as the runt of the litter, the 964 has found favour with a new generation of 911 owners. Moreover, the 964 Cabriolet is currently one of the most affordable classic Porsches.

IDENTITY AND SERVICE HISTORY

As ever, let's address the basics first. The 964 Cabriolet you're looking at should display a matching Vehicle Identification Number (VIN) on its V5 registration document and on the identification plate installed in the luggage compartment (attached to the right inner wheel arch). In the USA, the 964's VIN is also found on a plate attached to the left front A-pillar. This identifier can be viewed through the windshield when standing outside the car.

Elsewhere on the V5 document, you’ll see the engine number. Unless you've got the car on a ramp, this will be difficult to spot in the metal, but it's located on the engine block, on the right side of the crankcase next to the fan housing. You might be able to see it with the aid of a flashlight if the car is on the ground and you get on all fours.

Spend a couple of quid at mycarcheck.com, where you can download a history report outlining any insurance claims, change of registration number, recorded mileage and whether there’s any outstanding finance on the car. You should also enter the vehicle’s details into the DVLA’s free-to-use MOT history database, which can be found at bit.ly/dvlamot. The service will return all test passes, failures and advisories registered as far back as electronic records are stored (which is helpful in identifying any ongoing mechanical or safety issues). If you have the V5 document number at your disposal, you can even see which test centre carried out the inspection.

Damage may have been inflicted upon any 964 Cabriolet driven in anger, so check panel gaps are straight. Look for signs of mismatched colour and don’t be afraid to ask questions. You might be eyeballing a Porsche which has simply been tapped with a trolley in a parking lot, but then again, the car might have been stacked into a tyre wall at a race circuit. Either way, Porsche body repairs shouldn’t be done on the cheap. Ask to see receipts relating to the work, if applicable. A paint thickness gauge will help determine whether you’re looking at quarters full of filler.

Full service history, ideally accompanied by invoices for any work undertaken, is desirable when buying any used 911. These cars needs to be maintained by specialists with depth of model knowledge. General service garages are not likely to know the ins and outs of the 964's mechanicals.

Moreover, servicing at a general garage is an indication the seller (or previous owners) has likely skimped on spend, meaning the car is unlikely to have been cared for correctly. Lack of Porsche Centre or trusted independent specialist stamps in the service book will likely cause you problems come resale. It is far better to buy a 911 looked after by businesses well-versed in the care of these cars. There are plenty of 964 Cabriolets to choose from — don't be afraid to walk away if the paperwork doesn't please you.

Pay attention to recent documents in the car's history file. They may indicate which jobs are imminent, affording you the opportunity to negotiate a lower purchase price. Additionally, take advantage of an online VIN decoder, which will provide you with a Porsche-specific build sheet in exchange for a small fee. This document will let you know exactly how the car left the factory, including standard model specification and any optional extras.

EXTERIOR

964s were built using galvanised body panels, meaning even though the newest example was assembled three decades ago, you shouldn’t expect to find rust when inspecting your prospective purchase. That said, check around the windscreen seal, door bases, light apertures and wheel arches for paint bubbling or early signs of corrosion. Examine panel gaps carefully. 964s treated with less respect than this generation of 911 currently commands may have been driven carelessly.

Don’t be concerned about gravel rash or stone chips (these cars were meant to be driven fast, after all), but if the overall condition of the Porsche's bodywork is less than ideal, consider what other aspects of the car might not be in tip-top condition. Inspect all areas carefully.

Cabriolet roofs should be checked thoroughly for tears and nicks, especially around their edges. Faded black canvas can be restored through the use of application-specific restoration and waterproofing products from Renovo. If the soft top is the only thing letting down the 964 you're looking at, rest assured cabriolet roofs and/ or their plastic windows can be easily replaced. The parts are readily available on the aftermarket, either as individual items (e.g. headlining) or as a complete kit.

For many years, the 964 was the unloved 911 — surviving examples were often seen dripping oil and the subject of irregular servicing and maintenance. Today, a generation of Porsche fans who grew up in the 1980s and 1990s are rewriting history, lavishing expensive restorations and tuning upgrades on these cars. With this in mind, expect any 964 Carrera 2 or Carrera 4 to have received corrective paintwork in its recent history.

ENGINE AND TRANSMISSION

Early 964s are well-known for dripping oil at an alarming rate due to the manufacturer’s decision to not fit a gasket to the cylinder base. Later cars (1991 onwards) made use of a redesigned cylinder base and a seal designed to stop lubricant escaping, but 964s of all ages seem to like losing oil for fun — don’t be overly alarmed if there’s evidence of a drip on the seller's driveway. Be sure, however, to check the oil isn’t leaking from the oil pipes between the engine and oil tank. Replacement pipework isn’t expensive, but the tank is, and it may be damaged during pipe installation. Consider letting a specialist take care of this tricky job.

High-mileage 964s aren’t to be dismissed, especially if you plan to get regular use out of the car you’re thinking of buying. As is the case with almost all Porsche-engineered powerplants, the 964’s bottom end is rock solid, but top end rebuilds are needed the closer you get to the 100,000-mile mark. Signs the work is required include a drop in power and increased oil consumption. The fix includes fitting replacement valves, guides and piston rings.

Normally aspirated engines feature twelve spark plugs and twin distributors linked by a rubber belt. The belt weakens over time due to a build up of ozone within the distributor housing, eating into the rubber. If the belt snaps, you’ll experience an immediate lack of power, but if the rotor arm has stopped in an awkward place, it may continue to encourage a plug to spark, which will destroy the corresponding piston. Check service history to see when the belt was last changed.

Fortunately, a there’s an easy fix to cure the ozone issue: a retro-fitted 993 distributor air vent can be installed at the same time as a fresh belt.

Broken cylinder head studs can present themselves in the form of oil leaks, lumpy idle or misfire under load. The key to a successful purchase is to make sure you drive before you buy.

When it comes to turbocharged 964s, the same rules apply as you’d expect from inspection of a 930. In other words, look for blue smoke from the exhaust (a sign of failed turbocharger oil seals), excessive white smoke on start-up (oil making its way from the tank or pipes down to the crankcase) and lack of boost. If you suspect the turbocharger to be at fault, don’t be tricked into thinking you need to pay for a new part from a main dealer — specialist turbocharger repair and upgrade specialists will happily return your 964's faulty bhp booster to an as-new state. Furthermore, you may be surprised at how cost-effective it is to upgrade the car's turbocharger with modern internals while the repair work is being carried out.

You won’t have to search long before finding a 964 Carrera 4 owner who has converted their car's transmission to match the two-wheel drive set-up of the Carrera 2. There isn’t anything wrong with the Porsche fourby configuration, but many Carrera 4 drivers simply feel disconnected from their cars after experiencing the thrill of piloting a rear-drive model. At the end of the day, it comes down to personal preference. Test drive both types of 964 to determine which you prefer. Incidentally, the Carrera 4’s extra chassis equipment adds significant weight (resulting in easy understeer), but the model is recognised for being a brilliant tourer.

Early 964s suffer from a problematic dual-mass flywheel. Hugely unreliable, the part was replaced in all 964s in late 1992. Check to make sure the 964 you’re looking at is fitted with the later item. Signs you might be in possession of a car with the early design include heavy vibration at low revs, as well as lumpy idle.

From 1990, Carrera 2s were offered with the four-speed semi-automatic Tiptronic transmission, as fitted to our feature car. It’s a reliable bit of kit, but is an example of optional 964 equipment many think makes the driver feel less engaged with the car they're in charge of. If you’re tempted to buy a Tiptronic 964, then listen out for a noisy torque converter.

YOU WON’T HAVE TO SEARCH LONG BEFORE FINDING A 964 CARRERA 4 OWNER WHO HAS CONVERTED THEIR CAR TO TWO-WHEEL DRIVE

INTERIOR

964 interiors are typically hard-wearing, meaning there’s no need for you to take ownership of an example with ripped hide or worn carpets. Then again, the presence of seats in poor condition is a massive bargaining chip. Use it your advantage — replacement seats, carpets and headlinings are easy to come by. Professional upholstery repair or retrimming services aren’t exactly in short supply, either. Dave the Trimmer, Awesome Classic & Custom, Southbound Trimmers and Classic FX should be at the top of your shopping list.

Damp or discoloured carpets in Targas or Cabriolets is a sure-fire sign the soft-top of the 964 you’re looking at is leaking. As we've highlighted elsewhere in this buying guide, new Cabriolet roofs are readily available, although the motors powering them may need to be stripped and rebuilt if you experience problems with operation. On this note, check to make sure all of the car’s creature comforts work as they should. Particular attention should be paid to electric windows, seat movement, air-conditioning, dash dials and audio equipment, including speakers and the head unit.

Don't be fooled into thinking a tired interior requires a retrim. Advances in the restoration of automotive leathers (the process is often referred to as reconolising) has come a long way in recent years. Get in touch with professional detailing concern, Cambridge Concours, if the cabin of your 964 Cabriolet is looking shabby. Rather than replace old for new, there is the possibility of rejuvenating even the most tired of interiors, retaining original equipment and materials in the process. This may also save you money over a retrim. Leather preserver and balms will assist with ongoing care.

BRAKES, SUSPENSION AND STEERING

Out with torsion bars, in with coilovers. The suspension Porsche fitted to the 964 was fantastic, but as is the case with any older vehicle, rubber bushes deteriorate with mileage and the passage of time. New bushes are readily available from independent parts specialists, including Design 911, as are polyurethane replacement parts, providing you with a true 'fit and forget' solution, albeit at the expense of a slightly firmer ride. If you're concerned about the hassle of removing old bushes, then keep in mind the fact many new suspension components can be purchased with bushes pre-installed.

Even if you don't think the 964 Cabriolet you're looking at is in need of new supporting suspension components, it's worth investing in four-wheel laser wheel alignment in order to get the very best out of the 964’s handling capabilities. Rather than pop to your local tyre fitter for basic settings to be dialled in, we recommend visiting a dedicated chassis tuning specialist, such as Center Gravity, Suspension Solutions or Tuned UK, all of which are well-versed in the art of tweaking and tuning Porsche suspension systems. Long story short, these companies will use factory prescribed settings as a starting point, rather than the target. They'll ask you about your driving style, the kind of roads you travel on and the specifics of your Porsche, thereby enabling them to tune the chassis to suit your individual requirements. We've experienced the effects of this work firsthand — the improvements are massive and make for a far more enjoyable drive, as well as a more focused sports car.

The 964 was the first 911 to come fitted with ABS. This upgraded braking adds an extra level of safety to a much enhanced 911 package, but the age-old problem of aluminium calipers with backing plates made of steel can make pad replacement difficult. If in doubt, consult a specialist. Consumables are widely available on the aftermarket.

OVERVIEW

Targas and Cabriolets have long been the ‘great unloved’ variants of the formerly ‘great unloved’ 911, but as the photographs on these pages ably demonstrate, there’s absolutely no reason to dismiss an open-top 964, which is one of the shrewdest entry points into air-cooled Porsche ownership.

The 964’s condensed overall size, plus its relatively sparse cabin furniture, undoubtedly contributes to the sense of rapid pace, even when driving to the speed limit, but the sound of the standard M64 3.6-litre boxer singing away at the rear must also take credit here. It produces a joyous noise as you climb through the rev range, being simultaneously raucous and finely tuned to deliver both seat-felt bass and top-end holler. It's a wonderful orchestra of Porsche engineering at work, but sounds even more alive in a Cabriolet moving at full chat. It’s just as well you can pick up a 964 with a retractable fabric roof for half the cost of the equivalent coupe, then, isn’t it?

If there’s criticism to be levelled at air-cooled 911 Cabriolets, it is how the soft-top can look hunched up at the rear when retracted — the position of the flat-six doesn’t allow the roof to be stowed into the body shell. This is at odds with other convertibles of the era (shout out to the classic SAAB 900 fans among you) and makes the 964 Cabriolet's shape a little clumsy when viewed side-on. Porsche did much better with the same-age 968 Cabriolet, but in the grand scheme of things, we’re expressing a minor gripe, especially when the currently low price of buying an open-air 964 is extremely favourable compared to the cost of acquiring a tin-top. Go for a Tiptronic-equipped 964 Cabriolet — like the Porsche in our pictures — and the price drops even further.

Of course, we're not suggesting you can buy a 964 Cabriolet for the price your granny paid for her used base model Ford Fiesta, but to put the gulf between 964 coupe and Cabriolet prices into perspective, a quick search of online classifieds presented us with a tidy 1991 Cobalt Blue Carrera 2 drop-top with manual transmission, Linen leather, a Metropole Blue roof and a matching tonneau cover for a fiver short of forty grand.

Expect to pay more if you're looking for a Turbo Look Cabriolet or a very low mileage car, but however you shake a stick at it, there's no getting away from the fact you can find yourself as the proud owner of a very presentable 964 Cabriolet for less than the cost of a ropey 911 SC. Even the lowest mileage 964 Cabriolet we could find in UK sales listings was being offered at less than £70,000. A single-owner 1990 example finished in Grand Prix White and with just 28,600 miles covered from new, this Tiptronic-equipped, open air 911 is about as close as you can get to as-new condition for an air-cooled classic.

TRANSMISSION AND TUNING

Airflow upgrades (including free-flowing intakes and larger exhaust systems with 993 heat exchangers) rank high on the list of popular 964 mods, although there’s a lot to be said for taking influence from the RS by simply reducing the overall weight of your car. Remove cabin equipment you consider to be supplementary to requirements. This is a no-cost alteration and, as we all know, less weight equates to a quicker car. Talking of which, 964 seats are heavy. Composite buckets will make a big difference, albeit at the expense of comfort on long journeys. Manual steering racks will enable you to ditch a mass of hydraulic steering equipment and, as outlined earlier, converting a Carrera 4 to two-wheel drive will drastically reduce weight, as well as transforming the driving experience.

Gearing upgrades on manual cars will make for a snappier drive, while a lightweight flywheel will make the 964 rev much faster, although expect a more ‘agricultural’ transmission sound through reduced flywheel damping. ECU upgrades — either in the form of ‘off the shelf’ chipsets or standalone management — will alter fuelling and increase power. Turbochargers can be comprehensively rebuilt with modern internals at significantly less cost than a like-for-like replacement part. Sticking with the theme of forced induction, supercharger conversions have found a following on the 964 scene. And, of course, there’s the option of an engine transplant — fitting a larger displacement flat-six is a direct route to bigger bhp and more torque.