Porsche 911 (996) buying advice

Porsche’s fifth-generation 911, the 996, was a milestone – it was the first water-cooled 911, and, together with the 986-model Boxster, lead to the growth and prosperity of Porsche as we know it today. There was also much criticism leveled at the 996: besides the outcries of the air-cooled lovers, the “fried egg” headlights (as a cost-saving measure, a headlight design containing all bulbs in one unit was used, and the whole front end was shared with the Boxster) attracted much hate. Later on, issues with the M96 engines surfaced, giving the 996 and the 986 Boxster a reputation of unreliability. As a result, and due to the huge price increases for air-cooled models, these days the 996 is the most affordable 911 you can buy – but prices appear to be bottoming out, so now might be the time to buy. As affordable does not mean cheap, and parts and labor are expensive, it is important to have a thorough look at a car that you consider buying.

The buyer’s guide below is compiled from many sources on the internet. It aims at the Carrera 2 model, but most items are also relevant for the Carrera 4/4S.


Make a list of must-have and should-have options. These cars were pretty bare-bones without options. A/C was standard, cruise control was not. Partial leather was standard. Black interiors are wanted now, a light interior might be cheaper. Most of the cars are black, grey or silver, other colors may command a premium. The three-spoke steering wheel was a relatively cheap option that looks much sportier than the standard four-spoke wheel. Sports seats and sports suspension will probably command a premium now. A common option is the sunroof – you might like it if you want a weekend cruiser, someone who has track use in mind will probably want a car without sunroof. Other desirable options are the extended leather package, sports seats, the factory limited-slip differential (LSD), and the sports package.

Aero kits, especially GT body kits, are relatively common – some are factory, some are aftermarket. This is a matter of personal taste.

Maintenance record

A complete maintenance record/service history is the most important piece. If an owner has avoided the relatively expensive maintenance, walk away – chances are that the car has undetected issues that will prove costly in the future. Check especially for the items that are lots of work, such as the clutch and rear main seal.

Pre-purchase inspection

Consider having a pre-purchase inspection done at an independent Porsche specialist. This will cost a couple of hundred €/$. Even if you have prepared yourself with all the knowledge available on the internet, a specialist will know more and has specialist equipment to give the car a more thorough inspection, and prices for necessary fixes that you can use in your negotiations with the seller.


Rust is generally not much of an issue, but check usual suspects such as the wheel arches. The hood (or is it the trunk?) may have stone chips. Make sure the headlights are Ok as they are expensive to replace. The folding bellows under the rear spoiler may crack, and the access panel under the front hood (close to the windshield) may have gone missing.


The 996’s M96 engine is the part of the car that may cause the most expensive issues. A full engine rebuild isn’t much cheaper than buying a new 996. Over the years, several potential issues have surfaced.


The ECU registers two levels of overrevving. The first is when the engine is redlined/hits the rev limiter during acceleration. Many of such events hint at track use. If the owner is open about it, this doesn’t have to be an issue, but can be factored into the price negotiations. The second level is mechanical overrevving due to a missed downshift (e.g. from fifth to second). This can cause all kinds of issues, so it’s probably not worth the risk.

IMS bearing

Much has been written about the intermediate shaft (IMS) bearing. The GT3 and turbo models are not affected. The early years have a dual-row bearing that exhibits a low failure rate. Somewhere in 2000, Porsche moved to a single-row bearing that exhibits a relatively large failure rate (somewhere in the 5-10% range), without prior warning, usually resulting in catastrophic engine damage. Then in 2005, Porsche moved to a larger single-row bearing that exhibits a very low failure rate.

This means that if a car has the small single-row bearing, replacement is recommended. There are aftermarket bearings available that are more reliable, but these should be considered routine maintenance items. There’s also a permanent solution (or at least advertised as such) by LN Engineering, which converts the sealed ball bearing into an oil-fed journal bearing (just like the front IMS bearing). For peace of mind, changing a dual-row bearing can be advisable, too, especially if you are already doing work that requires removal of the transmission.

Unfortunately, if you car/engine was built in the transition phase from dual-row to single-row bearing, the only way to find out which bearing was used is by removing the transmission and measuring the IMS flange.

The later larger single-row bearing can only be replaced after complete disassembly of the engine.

If you buy a car that is likely to have the small single-row bearing and there is no evidence of it ever being replaced, take the necessary costs into account. If you have an IMS bearing replaced, have the rear main seal and clutch done at the same time.


The rear main seal (RMS) is located at the transmission end (i.e. towards the front of the car) of the engine, and a common point of oil leaks. Replacement requires removal of the transmission, so take this into account if the engine exhibits an oil leak at the engine/transmission gap.

Bore scoring

This seems to be an issue mostly with the 3.6l engine of the facelift model. A PPI should include borescope checks of all cylinders. Blackened exhaust tips on one side (probably the left) point to issues, too.


The early 3.4l engines seem to be somewhat prone to developing cracks in cylinder heads and cylinder liners. One opinion is that, if it hasn’t developed after 50,000 miles/80,000km, the engine will be fine. Nevertheless, checking an engine for these issues is advisable.

Air-oil separator

A failing air-oil separator (AOS) will be noticeable by exhaust smoke and sludge on the oil cap. This can cause big issues, so the AOS should be replaced regularly.

Coil packs

Coil packs are a common issue with modern cars. In the 996’s tightly packed engine compartment, they sit close to the exhaust. Make sure that they are Ok and that the heat shields are in place.


The mufflers are directly behind the rear wheels and hence constantly bombarded with whatever is on the road. They start rusting at the seam of the two halves. The stock mufflers are relatively quiet, so if a muffler replacement is due, you may consider an aftermarket exhaust if that’s your thing.

Both exhaust tips should look similar. If one is blackened while the other is clean, this points to issues with one cylinder bank – walk away.

Clutch and transmission

Check whether the clutch is slipping, try to find out when it was last replaced. A heavy pedal is a sign that a replacement may be due soon. A clutch job can be combined with the IMS bearing and RMS, as all three require the removal of the transmission.

The six-speed manual transmission has a reputation of reliability, just make sure it shifts smoothly. Shifting problems may point to worn gearbox and engine mounts. The throws with the stock shifter are quite long, short shift kits (both from Porsche and third parties) are available.


Thanks to the water-cooled engine, the 996 has much better heating than its predecessors. Air conditioning was standard. The condensers are mounted op front in the left and right corners. Leaves can collect here and rot, which will cause leaks in the condensers. Make sure that they are in good condition and that the A/C works properly. The coolant lines on the bottom of the car should also be checked for corrosion. The same is true for the radiators, which are located here as well.


One area where the cost-cutting shows is in the interior. There’s quite a bit of plastic here, and the soft touch coating is prone to chipping. The lighter interiors could be discolored. Check the seats for wear. I would consider the PCCM+ communication/navigation system a useful upgrade. The original PCM won’t be very useful today.


Suspension arms, bushings, and shock absorbers are wear items. Try to find out when they were last replaced. Drive the cars over speed bumps and listen for creaks. Check the shocks for signs of leaking. If you plan on doing suspension work, consider upgrading to decent shocks, possibly lowering springs (if the car came without sports suspension), or a good coilover set – especially when you want to use it on track.


Unlike some other brands (looking at you BMW), Porsche equips their cars with excellent brakes. The downside is that dealer-supplied replacement parts are relatively expensive, so make sure to check that rotors and pads are in good condition. Brake hoses may become brittle and brake lines rusty, so check these, too.

Wheels & tires

The car should be equipped with Porsche-approved N-rated tires that aren’t too old. If that is not the case, as the owner wanted to save money, he may have taken shortcuts elsewhere. Tires aren’t crazy expensive – a set of N-rated Michelin Pilot Sport PS2 in 17″ is approx. €600. The wheels should be in good condition. 17″ was standard, various 18″ wheels were optional.


A well-maintained 996 is a reliable and quick sports car that offers an analog driving experience (early cars even come with a cable throttle) without sacrificing modern comforts. Prices will probably rise in the future, so depreciation is no longer an issue. Common wisdom is to buy the best car you can afford, but I would consider an early (1998 or ’99, with the dual-row IMS bearing) car with >160,000km (100,000 miles) and a complete service record instead. Such a car should have lots of work done already and could be more reliable and a much better deal than a low-mileage garage queen with skipped services.

The 996 is actually a car that you can work on yourself. Yes, most engine work needs to be done from underneath, but the engine is exposed at the rear and accessible once the car is on jack stands. There are people who have done IMS bearing replacements in their garage. As is typical for Porsche, part supply is not an issue. So if you are on the fence about buying a 996, do it – it’s a future classic.

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