The used Porsche 911 to chase is a 997 Gen 2 or later, which has no IMS bearing to fail; on anything older, insist on IMS bearing paperwork and skip any car with milky emulsion under the oil cap.
2 known faults, 2 rated high severity in our database. Everything below is built from that data and the archived owner history, not from a press car.
Found a Porsche 911 for sale? Check the advert before you go and see it
Paste the Porsche 911 advert and we read it against its known faults, the MOT history and the DVLA record, then tell you what to ask the seller and what to look at on the day. Free, about a minute, no card.
Check a Porsche 911 advert (free) →Go for a 997 Gen 2 (2008 to 2012) or a later 911, because the engines fitted from the 2009 model year have no intermediate shaft at all, so the IMS bearing failure that can wreck an older engine without warning can't happen. Neither High known fault on file reaches these cars. A 2008 car can still be a 997 Gen 1 with the old engine, though, so be sure which one you're looking at.
On a 1998 to 2008 car, the IMS bearing is a High known fault on the M96 and M97, and which bearing the engine has decides the risk. 1997 to 1999 engines have a double-row one that seldom gives trouble, 2000 and 2001 engines could have either type, and the single-row bearing used after that up to 2005 fails most. The bigger bearing from late 2005 to 2008 fails far less but can't be changed without stripping the engine.
Within that era, a low-mileage early 3.4 996 from 1998 or 1999 is still the car to avoid, since bore liner trouble hit those hardest. Later 3.4s and the 3.6 were judged OK once past 30,000 miles, the top of the band where that trouble surfaced, but the 3.4, 3.6 and 3.8 built from 2004 to 2007 add cylinder bore scoring, so there's no older 911 without a serious engine check to do.
There's no known fault on file for the 991 (2011 to 2019) or the 992 from 2019, and owner reports on both are thin, which is a gap in the evidence rather than a clean bill. The 991's reports are about rattles, a few parts changed under warranty and stones thrown into the brakes, and the 992 has none at all, so judge either one on its history and how it drives.
None of the 1998 to 2008 engines is a safe pick on its own: every M96 and M97 carries some IMS bearing risk, and the 3.4, 3.6 and 3.8 built from 2004 to 2007 add cylinder bore scoring. Scoring brings piston slap and heavy oil use, and it ends with a dead engine if it isn't caught. The engines from the 2009 model year on have no intermediate shaft to fail.
The lesser risk on a 996 is a 3.4 from the 2000 model year on (its engine number carries a Y, where 1998 and 1999 engines show W or X) or a 3.6, once either is past 30,000 miles, the top of the danger band for liner trouble. Neither escapes the IMS fault, though, so on an engine up to 2005 you want proof the bearing's been replaced with an upgraded one, and on a later one, evidence that the oil filter's been checked for metal at services.
These engines use timing chains, and it's the IMS bearing that drives them, which is why the bearing matters far more than the chain. Wet-sump 996s can run short of oil when they're driven hard through bends, whereas the dry-sump GT3 and the Turbo based on it aren't affected by that particular problem.
On a manual 997, the gearshift cable can fail in as little as 15 months or 10,000 miles, and Porsche won't pay for a new one once the warranty's run out. Four-wheel-drive 996s can also be loud through the drivetrain, so hear one on the move before you commit to it.
Lift the oil filler cap and look in the coolant header tank before anything else: milky, mayonnaise-like emulsion or scum in either means oil and water have been mixing. Don't buy that car, because it's heading for a new engine and the muck spreads through the cooling system and heater matrix too, so fixing the engine alone doesn't clear it.
On the drive, listen for a loud rattle from the engine, which is how IMS bearing failure can announce itself, and for a ticking or tapping sound that points to piston slap from bore scoring. Afterwards, compare the tailpipes: one noticeably sootier than the other is a warning sign. One owner's report on the 3.8 Carrera S says a cylinder on the left bank runs hot and starts burning oil, and the left-hand pipe turning oily is the giveaway.
Look closely at the rear brake discs, since iron discs rust on cars that sit about or never get braked hard. Check the tyres are N-rated: one owner paid £42 each for two budget tyres on the back of a 996 and found the rear end felt loose until N-rated ones went on. On a 997, make sure the front boot lock works, as mobile phones have been known to upset its electronics.
Ask for bills for IMS bearing work, any engine replacement or bore liner repair, and a gearshift cable on a manual 997, plus proof that recall work was done. Ask whether a service has ever found metal debris in the oil filter. One owner advises seeing an ECU readout before buying a 997, because later cars log whether the engine's ever been over-revved.
Paste the advert into the free check and it runs these against the listing, the MOT history and the DVLA record before you travel.
It's worth buying only with paperwork on its IMS bearing and a clean oil cap, because the bearing's failure is a High known fault on every M96 and M97 in this era and the 3.4, 3.6 and 3.8 from 2004 to 2007 add bore scoring. What you get in return is a properly mechanical feel at the wheel, a car you have to work at to drive quickly, though there's more understeer than you'd expect.
The IMS bearing can go without warning and destroy the engine outright, and the single-row bearing used after 2001 up to 2005 fails most often. Bore liner trouble on the 996 surfaced by 30,000 miles, worst on early 3.4 cars, while bore scoring on the 2004 to 2007 engines shows up as a tapping noise and rising oil use. Oil and water mixing has also seen a lot of these engines replaced, so the oil cap check isn't optional.
On the 997, a defect in how some cylinders were bored at the factory is behind engine failures, and on a five-year-old car Porsche has sometimes met only part of the cost of a replacement engine, leaving the owner the rest. That's why a 997 with no paperwork on its engine isn't a bargain, whatever the mileage.
Recalls in this era fixed a wrong-size ancillary drive belt pulley on 1998 Carreras that could slip and affect the power steering, brakes, water pump and alternator; a loose power steering connector bolt on 996s that could leak fluid; and fuel line and wiring chafing on the 996 Turbo. Ask for proof each one was done on the car you're viewing.
Yes, a 991 is the easier buy of the two eras, because neither High known fault on file reaches it: its engines have no intermediate shaft, and bore scoring is recorded only on 2004 to 2007 engines. That's a gap in the evidence rather than a clean bill, though. One owner's 991 needed rattles curing, a suspension strut top mount and an oil separator, all sorted under warranty, so ask what's been replaced and when.
One 2015 991 cabrio owner found the front tyres flinging stones into the gap behind the brake discs, where they scraped loudly as the wheels turned, and through the radiator's outlet grille at the fan and radiator. Listen for scraping on the drive and look behind the front grilles. The sat nav won't take a full seven-digit UK postcode, and on a 2017 Cabriolet or Targa, ask for proof of the recall that rebonded a windscreen fitted with too little adhesive.
Sellers rarely admit these faults outright
Paste any Porsche 911 advert and we check it against the faults, the MOT record and these figures in seconds.
Check an advert now (free) →The 997/2 from 2008 is seriously quick yet usable every day, with handling that's hard to fault and a cabin that doesn't make a fuss. The PDK double-clutch gearbox is impressive too, and for all that pace, its economy is sensible enough to live with every week.
The 991/2 switched to turbocharged engines without losing the 911 sound, and it pulls harder low down for it. It's comfortable and easy to potter round town in, so it's a fast car that works as an everyday one. The newest 911, from 2019, has a 3.0-litre flat-six that isn't short of pull at any revs.
The used Porsche 911 to chase is a 997 Gen 2 or later, which has no IMS bearing to fail; on anything older, insist on IMS bearing paperwork and skip any car with milky emulsion under the oil cap. Our database holds 2 known Porsche 911 faults, 2 rated high severity, and the sections above say which generation and engine carry them.
Go for a 997 Gen 2 (2008 to 2012) or a later 911, because the engines fitted from the 2009 model year have no intermediate shaft at all, so the IMS bearing failure that can wreck an older engine without warning can't happen. On the fault record the 997 Gen 2 (2008 to 2012) carries no known faults against 2 on the 996 and 997 Gen 1 (1998 to 2008). Each generation's section above gives the detail. Porsche 911 faults by generation.
Lift the oil filler cap and look in the coolant header tank before anything else: milky, mayonnaise-like emulsion or scum in either means oil and water have been mixing. Read the MOT history for repeat advisories and ask for invoices for any work the seller mentions. Then paste the advert into the free check, which reads it against every known Porsche 911 fault before you travel.
Chain (M96, M97, 3.4, 3.6, 3.8): no fixed replacement interval, so budget for it if the history does not show it done. The known faults page lists a rough repair cost against each fault.
If you used the Honest John car-by-car reviews before the site closed in 2026, this is where the Porsche 911 buying advice now lives. It is written from the archived owner reports and model notes (archived page, 56 items read for this model), our own known-faults database, the confirmed service intervals and the Real MPG figures. Every number on the page comes from that data, not from the text. The same data feeds our free advert check.
CarAdCheck is not affiliated with Honest John or Volkswagen Financial Services. What happened to Honest John, and where each feature lives now.
The Porsche 911 is one decision. Reading the advert, the history and the seller are the rest, and these cover them.
Looking at a Porsche 911 right now? Check the advert before you go and see it.