Written by CJ Hubbard Updated: 22 September 2024

Overview

For all that it looks a bit funny – and we say that as an owner as well as an observer – this generation of Porsche 911 was a turning point for the company. For the Type 996, as the 911 built between 1997 and 2004 is known, was the first 911 to switch from air-cooled engines to water-cooled engines, setting the foundation for the future of this legendary sportscar as we know it today.

Sharing parts with the 986 Porsche Boxster that was developed alongside it and 911 Type 993 that preceded it (as well as the 997 that followed), despite early criticism of its appearance and what some saw as the dilution of the 911’s traditional rear-engine driving dynamics, it proved to be a big success for the company.

These days it represents the least expensive entry-point into a used 911, which can make it temptingly affordable. But you should be aware that the old adage ‘there’s no such thing as a cheap Porsche’ really does ring true when it comes to servicing and maintenance, and there are some notorious 996 issues that can lead to very big bills.

Porsche 911 996 known faults and common problems

Bought carefully, these are brilliant cars. The structure is strong and stiff, they’re lightweight by modern standards, and still feel pretty quick. But if you buy the wrong one you could be in for a real nightmare. There are well known engine issues, the suspension components wear out rather quickly, and they’re starting to rust now, too.

To this end, while we’ve provided a list of the 10 most vital problem areas to check on below – filtered by our own buying and running experiences and concerns – we would strongly advise you to get a professional inspection of any second-hand 911 before you purchase. This might seem an annoying extra cost, but it could save you from making a very expensive mistake. A good car history check is the very least you should do.

Buying guide

Common issues, and what to look for if you’re thinking of getting one

1. IMS bearing

This is the famous 996 issue – failure of the intermediate shaft bearing, which can take the engine with it. It only affects Carrera and Carrera 4 models (the Turbos and GT cars use different engine designs), and no-one really has any idea how many cars have actually suffered a catastrophic incident. But it’s likely to be a single-digit percentage.

It can impact any age of relevant 996, though the earlier dual-row IMS bearings are thought to be stronger, and higher mileage cars are likely to be less problematic since their bearings are probably being lubricated by the engine oil by now. No guarantee, though. Various aftermarket fixes are available, but replacement is an expensive engine-out job, so many advise you look for a used 996 where the work has already been done.

Just make sure it was carried out by a reputable specialist using a reputable solution. Whichever way you want to play it, seek out cars with proper service history, as regular maintenance means consistently fresh oil and any specialist worth the name will be checking the oil filter for metal particles each time.

2. Bore scoring

This is the other slightly less famous but potentially terminal 996 engine issue. The ‘open deck’ engine design means that in some circumstances, the cylinders – particularly number six – may go oval, wearing away the liner and causing excessive oil loss that will eventually lead to total failure.

The only true fix is an engine rebuild. Telltale signs are excessive oil smoke, especially after the car has been stood for a while – and usually indicated by a sooty tailpipe, most likely on the left side; a ticking noise, similar to a stuck hydraulic lifter; very black engine oil on the dipstick. You might also get misfires and poor idling, but there are other things that can cause that, too.

Similarly, a failing oil-air separator can cause a smoky exhaust, so don’t despair too soon. A professional inspection including an examination inside the cylinders is the only non-invasive way to be sure, and even then it’s not 100%. Again, 911s that have seen plenty of fresh oil via frequent servicing are less likely to have such damage. High quality fuel is good insurance, too.

3. Oil leaks and other engine issues

Oil leaks in these can be tricky, as there’s a lot of under-body cladding, but weepy engine seals – particularly the rear main seal, known as the RMS – are common. Not necessarily a big deal as long as you keep an eye on the levels.

Since you’re there, look at the coolant as well. Related plastic parts expire with age, and you want to spot that early to avoid over-heating. Check the fans at the front while you’re at it – you should hear them kick-in higher at idle when you switch on the air-con. If not, a fan resistor replacement may be due; we’ve found it cheaper to replace the entire fan.

Other engine issues include failing coils and leads, warn out spark plugs, and a variety of things that can cause poor starting. Broken exhausts can cause running problems, too, and the manifolds tend to break their fixings when removed (though there are solutions for this). Some believe the engine runs too hot as standard, so fitting a cooler thermostat isn’t unusual.

If you see a 996 advertised with a rebuilt engine, don’t be put off. Done properly this costs upwards of £10,000 and will significantly extend the life of the car. Just make sure the builder was a good one; you don’t want to have to do it again because the previous outfit didn’t know what they were doing.

4. Brakes and Suspension

These are fast cars with big brakes, and the related components are expensive – it’s upwards of a grand just in parts for a full set of discs and pads. The brake fluid should be changed every two years – so look for this in the service history. The brake pipes corrode, too, so check the MOT history for evidence of this and appropriate rectification. Be aware that one pipe in particular may require the engine to be removed for replacement…

The handling should be sharp, detailed and very responsive, with firm damping that keeps the car tightly controlled and smooth power-assisted steering. Knocking noises over bumps are signs of failing suspension components, some of which are easy and relatively cheap to replace, others not so much. Be wary of ‘upgraded’ suspension, as the quality of this varies tremendously and is often to very personal taste.

If the suspension has been replaced or repaired, find out who did the work, and investigate their reputation. A proper geometry set-up is vital on these to keep them cornering sweetly, again requiring a decent specialist.

5. Alloy wheels and tyres

The weight of the different alloy wheel designs varies widely, and can have a big impact on ride and handling. However, some of the lighter wheels also don’t like a big impact – such as from potholes. So examine carefully for bends and buckles, and be alert to vibrations when driving.

Tyres should be matched premium brand. Accept no excuses. Rubber this size is expensive – especially the unusually wide tyres at the rear – and budget items suggest an owner who couldn’t afford to keep up proper maintenance. Porsche has an N rating scheme for factory-approved hoops, but there hasn’t been much of a move to keep up with modern tyre technology for the 996, so don’t feel this is essential as long as the tyres are high quality and performance-orientated to recent specifications.

6. Interior issues

Look for signs of water ingress (the sunroof drains can block) and sun-damage (such as faded carpets). Listen for rattles and creaks – the latter sometimes the result of a poorly fitted replacement windscreen. Expect the lid of the ashtray in the centre console to not stay back down without taking the ashtray out. Look for scratched finishes that indicate a careless previous owner. Leather may be worn on the seat bolsters but seldom completely damaged. Check both doors open from all handles, and that they both lock.

Be aware that these are loud cars inside, with not much in the way of truly effective sound deadening, so can be quite tiresome on longer journeys. Aftermarket exhausts will make this worse.

Deactivating the passenger airbag so you can fit a child seat in the front requires a tweak to the ECU (most Porsche specialists will be able to do this) but also a special accessory bar that mounts under the seat and only interacts with Porsche child seats of the period. Typical. There are third-party solutions if you hunt carefully on eBay but we cannot vouch for their integrity.

7. Aging electronics

Does everything work? The liquid crystal displays – in the instrument cluster and the climate control – fail over time; if you’re lucky this will only be minor and even intermittent. The radio may develop a mind of its own. The sunroof can jam. The alarm can go bonkers, and god help you if the immobiliser stops working.

Battery drains are common, though in our experience this can be lessened by upgrading to a newer AGM (absorbent glass matt) type battery – make sure you get a branded one of the correct large capacity. The ignition switch can fail and the cigarette lighter may not work, but both these are inexpensive and easy to fix.

8. Does the air-conditioning work?

Do not let the vendor tell you these cars never get particularly cold inside, because if the air-con is working properly this simply isn’t true. You should be able to detect a temperature difference between it being switched on and off (and believe us, there’s a lot of glass and a small cabin, so you will get hot if the air-con isn’t functional).

If you can’t tell the difference, there’s a problem. Could be something simple, such as busted condensers, a common failure point and an easy repair. Or it might be a leak in a pipe that can’t be replaced unless – you guessed it – the engine comes out. Other heating and ventilation issues require the removal of the dashboard.

9. Clutch and gearbox problems

Manual gearboxes should feel taut and precise. If not, you might be lucky and a zip tie may sort it out (yes, this kind of hack is common, even on Porsches) – or you could be looking at new cables. Does the clutch have plenty of bite? Replacement is inevitably costly.

The Tiptronic S automatic got a lot of stick when the 996 was new due to its unusual manual-override flippers on the steering wheel and comparative lack of involvement, but there are some advantages from a used purchase perspective. For instance, it’s highly unlikely that the engine will have been over-revved – something that’s easily done when downshifting in the manual (specialists can check for this via an ECU query; over-revving can damage the engine), and most Tips will generally have had an easier life.

But you’ll want evidence of a recent transmission oil change, or budget a hefty amount for getting it done ASAP. The gearbox should also shift smoothly when driving, without any worrying clunks or flashing indicator lights, and cleanly engage Drive and Park – if not it might need new cables, a new switch (£££) or control module (££££), or if lucky, just a bit of grease and adjustment.

Early 996 ZF autos weren’t very bright, either, but facelifted 3.6-litre cars had a Mercedes automatic with more adaptability thanks to a much larger choice of mapping patterns.

10. Rust

The 996 was fully galvanised from new, but this is a sacrificial process and likely to be worn out by now. Check the wheel arches carefully and as much of the under side as you can examine – again, there is lots of cladding, which doesn’t make this easy. Be warned that repairing a rusty 911 is unlikely to be a cheap business, as there will almost certainly be more corrosion to find once you begin.

What models and trims can you buy?

Porshe doesn’t really do trim levels. Instead specification varies with engine. For the 996 generation there are rear-wheel drive Carrera (sometimes known as the C2 or Carrera 2), all-wheel drive Carrera 4 (C4), the all-wheel drive wide-body Carrera 4 S (C4S) and the all-wheel drive wide-body Turbo models. Not to mention a 40 Jahre Edition based on the C2, the first ever 911 GT3 and the turbo equivalent 911 GT2.

A midlife facelift in 2001 brought in revised engines – the 3.4-litre Carreras becoming 3.6-litre models – and revised the controversial headlights so that the 911 no-longer resembled the cheaper Boxster it shared so many parts with. Various upgrades included factory tweaks to power outputs and suspension, while the interiors were offered in a wild selection of factory colours.

There are services available online that will give you the build-spec of a particular car from the vehicle identification number (VIN). This can be worth investigating, as often the label listing options under the bonnet is faded, and although this should also be in the original service book, sometimes not all of the options are on it.

Desirable specifications that aren’t so easy to come by include early cars that use a throttle cable instead of drive-by-wire electronics, no sunroof (it was standard and had to be deleted from the order; enthusiasts say it makes the car stiffer and lighter), and a mechanical limited slip differential.

There was a 996 convertible as well as the coupe covered here. These are often cheaper to buy used, but come with additional complications related to the drop-top roof.

Over the next few pages, you’ll find our original impressions of the 996-generation Porsche 911, covering its practicality, comfort, fuel economy and performance. If you’re short on time, you can also skip to our verdict page to see if we recommend the 996 as a good used car.