THE PROBLEMS Engine cylinder bore wear

On both the 3.6 and 3.8-litre engines the cylinder bores can become scored, leading to excessive oil consumption and a lack of cylinder compression. The problem of scored cylinder linings is widely thought to be rooted in the switch away from the old Nikasil-coated linings used on Porsche’s aircooled engines, the 997 engine’s Lokasil linings prone to deterioration, as indeed are the 996’s. ‘It tends to be the right-hand side as viewed from the rear of the car that fails,’ Steve explains. ‘The sign of the problem is the left-hand exhaust tail pipe having become blackened.’

There is no cheap fix, the remedy an expensive rebuild. But some 997 engines are completely unaffected, and it is the Carrera S engine that is much more likely to have developed the problem. Steve reckons it’s more common on cars that are driven infrequently.

IMS bearing failure

The IMS (intermediate shaft) is positioned below, and takes its drive from, the engine crankshaft and provides drive for the oil pump and the camshaft chains. Failure of the IMS bearing can displace the cam chain, knock out the valve timing and cause anything from bent valves to major engine damage.

‘There are very few signs that it is about to go,’ Steve warns. ‘You may be lucky and see an oil leak from between the engine and transmission, or the bearing might start to make a screeching noise.’ Various Porsche specialists offer their own uprated bearings, but others prefer to stick to Porsche replacement parts.

Suspension

As on many modern coil-sprung cars, springs can randomly break, in the 997’s case at the bottom, where they sit in their mounting cup. ‘You’re not going to notice the problem, but it will be picked up by the MOT tester,’ Steve tells us. ‘They can also snap higher up, and if it does snap in the middle the car falls down at one side.’

Air conditioning

If the two air con condensers mounted at the front of the car on each side, and attached to the water radiators, haven’t been replaced, they may well be leaking and not allow the system to produce cold air. ‘These are anodised aluminium without much protection, and they pick up a mixture of road salt, leaves and damp, which leads to corrosion,’ Steve explains. ‘Look for an oil stain on the condensers, this is the sign of a leak.’

Brakes

Has a 997 been hard used at track days? Look closely at the brake discs and if you see micro cracks in the surface then it probably has. ‘Discs can last 20,000 miles, but you can cause premature wear in one afternoon on a track,’ Steve comments. Yellow calipers denote the factory ceramic brakes. These are hugely expensive to replace, but not many Carreras, especially not the 3.6, had them.