If you are considering buying a used Porsche 911, there are several major reliability issues worth knowing about first. Our garage database tracks 2 known faults for this model, 2 of them rated high severity. Every one below is a repair bill a seller has good reason not to mention.
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metallic debris in the oil filter during servicing
loud rattling noise from the engine
sudden and complete engine failure
Affected vehicles
Engines:
M96 / M97 (Non-Mezger)
Typical mileage:
40000-80000 miles
1 more owner report backs this up
June 2011The most common serious problem reported for this model appears to be failures of the engine's intermediate shaft bearing.
🔍 We have a specific pre-purchase check for this faultCheck an advert →
Engine/EmissionsHigh severity💬 Owner reports
Cylinder bore scoring causing piston slap, high oil consumption, and eventual engine failure
Rough guide
£8000-12000
Typical symptoms
ticking or tapping noise from the engine (piston slap)
high oil consumption
one exhaust tailpipe noticeably sootier than the other
Affected vehicles
Engines:
3.4 / 3.6 / 3.8 (M96/M97)
Typical mileage:
50000-90000 miles
1 more owner report backs this up
August 2015A 3.8 water-cooled Carrera S engine experienced overheating in one cylinder, damaging gaskets and causing oil burning and eventual cylinder bore damage.
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What owners report on the 996 / 986 / Early 997 / Early 987
5 single reports, unconfirmed
One owner each, in their own words rewritten as a line, and not counted in our risk scoring. A fault joins the list above once a second report or an editorial source backs it.
Suspension and steering · November 2016A Porsche 996 owner experienced very loose rear handling with cheap £42 Haida tyres, which improved dramatically after fitting Porsche-recommended N-rated Continentals.
Electrics · March 2015A 1997 to 2004 Porsche 911 996 was ranked the third least dependable European car in a warranty claims survey; electrical problems were the most frequent issue.
Electrics · February 2015The engine control unit in later Porsche models records usage, including any over-revving, which is crucial to check before buying a used 997.
General · December 2012A 2001 to 2006 Porsche 911 996 was rated the eighth most likely car built between 1997 and 2009 to suffer expensive problems in a reliability index.
General · September 2012Collapsible spare tyres on this model can only be inflated and used once, requiring replacement afterwards.
What owners like about the 996 / 986 / Early 997 / Early 987
6 notes
May 2012This model achieved the eighth highest first-time MoT pass rate at 87% among models with over 2000 examples.
The 911 Turbo offers a wonderful mechanical feel to drive, requiring engagement from the driver.
This model delivers impressive performance while also offering surprisingly good fuel economy for its class.
The car provides sublime handling characteristics and features a fuss-free cabin design.
This Porsche 911 is a very usable high-performance machine suitable for everyday driving.
The PDK double-clutch gearbox fitted to this model is highly impressive in its operation.
Other years0 known faults · 4 owner reports · 8 good notes
Other Porsche 911 years: owner reports
What owners report
4 single reports, unconfirmed
One owner each, in their own words rewritten as a line, and not counted in our risk scoring. A fault joins the list above once a second report or an editorial source backs it.
Bodywork · March 2016A 2015 911 991 cabrio at under 3,000 miles had front tyres firing stones into the disc brake backplate and radiator, with no fix available.
Engine · November 2013An £87,000 Porsche 911/991 experienced multiple problems, including numerous rattles, a suspension strut top mount change, and an oil separator replacement, all fixed under warranty.
Electrics · March 2012The navigation system in this model will not accept seven-digit UK postcodes.
General · March 2012This model still comes with only a two-year full factory warranty, with the third year provided as an insurance policy.
What owners like
8 notes
The move to turbocharged engines has improved the 911, offering the same sound but with better low-down response.
The 911 is comfortable and easy to drive around town, making it a high-performance car suitable for daily use.
The change to a twin-turbo 3.0-litre engine should theoretically result in slightly better fuel economy.
Porsche Active Suspension Management (PASM), which lowers the ride height by 10mm, is included as standard equipment.
Navigation and DAB radio are included as standard features on all cars in this model range.
From 2019, this model features a proximity key disabling system to prevent key signal boosting and relay theft.
The 3.0-litre flat-six engine provides abundant torque across the entire range of engine speeds.
This model features a notably impressive interior, praised for its design and overall build quality.
Sellers rarely admit these faults outright
We track 4 specific phrases sellers use in adverts to soft-pedal these exact issues. Paste any Porsche 911 advert and we check it in seconds.
Porsche 911 service intervals: cambelt, chain and gearbox oil
An overdue cambelt is the most expensive thing a seller can fail to mention on a used 911. These are the figures UK specialists work to.
Timing chainChain
M96, M97, 3.4, 3.6, 3.8
No fixed replacement interval
The M96/M97 engines use timing chains. However, the far bigger concern is the Intermediate Shaft (IMS) bearing which drives the chains. This bearing can fail catastrophically and should be proactively upgraded.
Always confirm against the vehicle handbook. Intervals vary by engine, and several manufacturers revised theirs after failures in service.
Repair costs are typical UK ranges, not quotes. Actual cost depends on condition and garage.Data last verified: June 2026
Porsche 911 buying questions
Is a used Porsche 911 reliable?
The Porsche 911 has 2 known faults in our database, 2 of them rated high severity. The most serious are engine (intermediate Shaft (IMS) bearing failure causing catastrophic engine destruction without) and engine (cylinder bore scoring causing piston slap, high oil consumption). None of them makes the car a bad buy on its own; the risk is a seller who knows and says nothing.
Which Porsche 911 years should I avoid?
No Porsche 911 year is a write-off, but the 996 / 986 / Early 997 / Early 987 (1998 to 2008) carries the most serious faults: engine. Year matters less than whether the specific car has had the known fixes, so check the history for them.
What should I check when viewing a used Porsche 911?
Ask the seller about the engine faults on this page and whether they have been fixed, with invoices. On the test drive watch for metallic debris in the oil filter during servicing and ticking or tapping noise from the engine (piston slap). Read the MOT history for repeat advisories, then paste the advert into the free check, which reads it against its known faults before you travel. Check a Porsche 911 advert →
If you used to check the Honest John “Good & Bad” section before the site closed in 2026, this page is where that information now lives. We rebuilt the Porsche 911 owner-report history from the archived Honest John dataset, added our own research, specialist and owner-club sources and DVSA recall data, and we keep it free. Each fault above is badged with its source. The same data feeds our free advert check, which reads a listing against every known fault for the exact engine and year.
Knowing what a Porsche 911 goes wrong with is half of it. The rest is reading the advert and checking the car's history before you hand any money over.