Porsche 911 (997) buying guide

The 997.1 used a 3.6-litre flat-six with 325 hp in the Carrera and a 3.8-litre with 355 hp in the Carrera S. Gearboxes were a six-speed manual or a five-speed Tiptronic. The 997.2 update brought direct fuel injection, 345 hp in the Carrera and 385 hp in the Carrera S, plus a choice of six-speed manual or seven-speed PDK. It also added LED daytime running lights and new LED taillights.

The 997.2 engine was a full redesign with a re-engineered cylinder head and no intermediate shaft. ZRG Classics and RennDriver both call the 997.2 the safer buy for that reason. ZRG still rates an early car as a fine one if it comes with a clean bore scope and IMS paperwork. Our 997.2 Carrera S page and 997.1 Carrera S page show what is listed.

RennDriver and FlatSixFinder both pick the 997.2 Carrera S as the best-balanced car in the range. It has the larger engine, standard PASM and bigger brakes than the Carrera. The Carrera GTS arrived in 2010 as a 997.2 only, with 408 hp from the 3.8, the wider Carrera 4 body, sports exhaust, Sport Chrono and centre-lock wheels. JBR Capital calls it the best 997 to buy, a sleeper and a keeper. Magneto calls the manual GTS the ultimate 997, though it adds that plain Carreras can be the sweetest.

JBR also rates a rear-drive manual Carrera coupe as one of the great all-rounders, so see the 997.1 Carrera and 997.2 Carrera pages too. On the Targa, JBR reports criticism that the canopy raises the centre of gravity and costs a lot to fix if its internals fail. On ceramic brakes, ZRG's advice is to pass on PCCB unless you can pay for new discs when they wear out.

The serious worries sit in the 997.1 engine, and the sources put different numbers on them.

Bore scoring

Porsche Club GB puts bore scoring at perhaps 5% of 997.1 cars, with the 3.8 S engines more prone. Tiptronic cars appear to suffer more than manuals. Look for an oily deposit on the left exhaust pipe, ticking at idle, and one exhaust tip more coked than the other.

IMS bearing

Early 997.1 cars have a small IMS bearing, and wittwer.nl puts its failure rate somewhere in the 5-10% range. A stronger bearing arrived around the start of the 2007 model year, and Porsche Club GB says most experts see low risk on those cars. Wittwer dates the larger bearing to 2005 and calls failures very rare, so the sources differ on timing.

Rear main seal and separator

The rear main seal can drip oil, and the repair can be done during a clutch replacement. Cars from 2007 onwards are less affected. A failing air-oil separator shows as exhaust smoke and sludge on the oil cap.

Intake valve carbon

Direct-injection 997.2 engines can build carbon on the intake valves, which brings rough idle and misfires. FlatSixFinder says walnut blasting typically costs $500 to $800.

Cooling system leaks

Radiators behind the front bumpers can block with debris and leak. The rubber coolant crossover pipes can corrode too, and both repairs are expensive.

Exhaust flaps and bushes

PSE exhaust flaps can seize from lack of use and cost a lot to fix. Separately, front suspension-arm bushes wear, giving uneven tire wear and clonks over white lines.

JBR Capital gives service intervals as every two years or 20K miles. It also puts a new clutch at close to £1000 (a UK figure), lasting 70 to 80,000 miles.

The big bill is the engine. Wittwer says a full rebuild can easily pass 15k (it gives no currency). Carbon cleaning on a 997.2 is far smaller at $500 to $800 per FlatSixFinder, but exhaust flaps, coolant pipes and ceramic brakes are all described as expensive when they fail.

If avoiding the IMS bearing matters most, buy a 997.2, and the Carrera S or the GTS are the ones the sources single out. The 997.2 still needs a check for intake valve carbon. If you prefer the 997.1, look for a 2007-on car with a clean bore scope and IMS paperwork, and be warier of a 3.8 S or a Tiptronic.

Whichever you pick, have a specialist read it with a PIWIS before you commit, and keep the engine rebuild figure in mind when you haggle over a car with gaps in its history.