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Porsche 911 car check

Find out if a Porsche 911 has outstanding finance, has been written off or stolen, how many owners it’s had, and which known problems apply to the generation you’re looking at.

Finance, stolen, write-off and owner history data provided by Experian. Results in under a minute.

Typical price
£83,394288 at dealers
MOT failure rate
12.3%164k tests
Known problems
10across 996 to 992
Full report
£7.49one-off, no subscription

Which 911 are you looking at?

Each 911 generation has its own weak spots. Pick the one you’re viewing to see what to check.

  1. IMS bearing failure

    Safety risk 996, 997

    The intermediate shaft (IMS) bearing supports the shaft that drives the camshafts in M96 flat-six engines. The original single-row ball bearing is undersized for the loads it carries and can fail without warning, sending metal debris through the entire lubrication system. This is the most extensively documented catastrophic failure mode on 996-generation Porsches, with rebuild costs that routinely exceed the car's market value. Early models (1997-2001) are most at risk due to the smaller bearing design.

    What to check: Pull the dipstick, wipe clean, dip again, and examine the oil in direct sunlight. Look for any metallic sparkle or fine silver particles - this indicates bearing metal shedding. Ask the seller whether the IMS bearing has been proactively replaced and request invoice documentation. Look for LN Eng...

  2. Bore scoring (less common than 997.1)

    Safety risk 997, 991

    Cylinder bore scoring occurs when the piston rings lose sealing ability and allow metal-to-metal contact between pistons and cylinder walls. Both 3.6L and 3.8L flat-six engines are affected, though less severely than 996 and early 997.1 models. Lokasil cylinder linings are particularly vulnerable to scoring from contaminated oil or overheating. Complete engine rebuilds with new cylinders are the only permanent solution.

    What to check: Check exhaust tips for black soot deposits indicating oil burning. Ask about oil consumption between services - more than 1 litre per 1,000 miles suggests bore damage. Request a borescope inspection report if available - this is the definitive diagnosis method. Check oil level and condition for m...

  3. Coolant pipe failure

    Safety risk 996, 997

    The Mezger flat-six engine in GT3 and Turbo models uses different coolant routing than the M96, with additional cooling pipes that can corrode and fail. While the Mezger engine itself is extremely robust, coolant loss from pipe failure will cause overheating and serious engine damage. The pipes are located in areas prone to corrosion from road salt and moisture.

    What to check: Check all visible coolant pipes for corrosion, weeping, or white residue indicating leaks. Inspect pipe connections and jubilee clips for corrosion. Look for coolant staining on undertray or ground. Check coolant level for unexplained loss.

  4. Cylinder bore scoring

    Safety risk 996

    The M96 flat-six cylinder bores can score due to insufficient lubrication, particularly on the cylinder 6 bore which runs hotter and receives less oil flow. This creates vertical scratches in the cylinder walls that allow oil to pass the piston rings. The 3.6L engines are more susceptible than 3.4L variants due to higher specific output and thermal stress. Once scoring begins it progressively worsens and cannot be reversed without a complete engine rebuild.

    What to check: Check exhaust tips for black carbon soot deposits - a key indicator of oil burning. Ask about oil consumption between services - more than 1 litre per 1000 miles indicates internal wear. Request maintenance records showing oil top-up frequency. A pre-purchase borescope inspection by a Porsche spe...

  5. Cracked cylinder liners

    Safety risk 996

    The M96 engine uses Nikasil-coated aluminium cylinder liners which can crack due to thermal stress or manufacturing defects. When cracks penetrate the water jacket, coolant enters the combustion chamber and oil system, causing catastrophic internal damage. This is distinct from bore scoring and represents complete structural failure of the cylinder walls requiring full engine replacement or rebuild.

    What to check: Check oil filler cap for white mayonnaise-like emulsion indicating coolant contamination. Check coolant reservoir for oil contamination or brown discoloration. Look for unexplained coolant loss without external leaks. Check dipstick oil for coolant contamination.

  6. Spun camshaft sleeves

    Safety risk 997

    The camshaft sleeves on 3.6 twin-turbo engines can slip or spin within the camshaft assembly, causing catastrophic timing disruption. This occurs when the interference fit between the sleeve and camshaft degrades, usually due to heat cycling and oil contamination. The failure affects valve timing and can cause piston-to-valve contact, requiring extensive engine reconstruction.

    What to check: Check for any stored engine fault codes related to camshaft position or timing. Ask if camshaft sleeves have been inspected or replaced as a preventative measure. Review service history for regular oil changes - contaminated oil accelerates sleeve degradation.

  7. Wheel bearing excessive play

    Wear item 996, 991, 992

    MOT data shows 996 models fail wheel bearing tests at 118.2 times the national fleet average, indicating a specific design issue or accelerated wear pattern. Wheel bearings support the wheel assembly and allow rotation while maintaining precise positioning. Excessive play affects handling precision, causes tyre wear, and in extreme cases can lead to wheel detachment representing a serious safety risk.

    What to check: Check for any grinding or rumbling noise from wheels when car is moved by hand. Inspect tyres for uneven wear patterns indicating wheel alignment issues from bearing play. Look for any visible play when rocking the wheel by hand.

  8. Lambda sensor outside limits

    Engine damage risk 996, 997, 991

    MOT data shows 996 models fail lambda sensor emissions tests at 317.3 times the national fleet average, indicating widespread sensor degradation or related system issues. Lambda sensors monitor exhaust oxygen content to maintain correct air-fuel mixture. Failure causes poor running, increased emissions, potential catalytic converter damage, and MOT failure. The high failure rate suggests sensors may be affected by oil contamination from AOS failure or bore scoring.

    What to check: Check for any engine warning lights on the dashboard. Ask about recent emissions test results or MOT failures. Request diagnostic scan for lambda sensor fault codes.

  9. Rear main seal (RMS) oil leak

    Engine damage risk 996, 997

    The rear main seal sits between the engine crankshaft and gearbox and prevents oil from leaking at this critical junction. On M96 engines, this seal commonly fails due to crankshaft end-float issues and pressure variations from the IMS bearing. The repair requires either engine or gearbox removal, making it extremely labour-intensive despite the seal itself being inexpensive.

    What to check: Look underneath the car at the engine-gearbox joint for oil accumulation or fresh drips. Check for oil staining on the undertray or ground where the car is parked. Inspect the clutch housing area for oil seepage. Ask about burning oil smells during driving.

  10. Suspension wear and refresh needed

    Wear item 996

    Due to age, most 996s require comprehensive suspension component replacement including bushes, drop links, dampers, and alignment. The sophisticated suspension setup that gives the 911 its handling prowess becomes vague and imprecise as components wear. This is particularly critical on GT3 models where worn components completely ruin the handling balance and precision.

    What to check: Check tyres for uneven wear patterns indicating alignment or suspension issues. Look for oil leakage from dampers. Visually inspect visible bushes and drop links for cracking or deterioration.

What 911s cost at dealers now

From 288 used 911s we track on UK dealer websites.

Typical asking price
£83,394
Typical mileage
39,641 miles
Price change vs last month
+8%

911 MOT results

12.3%

of 911 MOT tests end in a fail, from 163,980 tests.

Most common reasons for failing

  1. Emissions failureExhaust & Emissions
  2. Tyre valve seriously damaged or misalignedTyres
  3. Light unit faultLights & Electrics

Check the 911 you’re buying

One report covers outstanding finance, write-offs, theft and previous owners from Experian, plus MOT history, mileage and the known problems for its generation.

Finance, stolen, write-off and owner history data provided by Experian.

What the check includes

911 questions

Is the Porsche 911 reliable?

12.3% of 911 models fail their MOT based on 163,980 tests analysed. That’s better than average for the class. There are 10 known problems to watch for, the most serious being ims bearing failure. A full history check shows whether a specific car has had related write-offs or insurance claims.

What are the main problems with a Porsche 911?

The most serious known issues are ims bearing failure, bore scoring (less common than 997.1), coolant pipe failure. Problems vary by generation, so check which apply to the year you’re looking at. Our car check flags whether a specific 911 has been written off or had insurance claims linked to these faults.

How do I check if a Porsche 911 has outstanding finance?

Enter the registration on this page. We query Experian’s finance database and return any outstanding agreements within a minute. If finance is still owed, the finance company can legally repossess the car even after you’ve paid the seller. At £7.49 it’s the cheapest way to avoid a car that isn’t legally for sale.

How do I check if a Porsche 911 has been written off?

Our check queries Experian’s insurance write-off database for Cat A, B, S and N markers. A Cat S or N 911 has been structurally or non-structurally damaged and repaired. This doesn’t mean it’s unsafe, but it affects resale value and some insurers won’t cover it. The check costs £7.49.

Can I check a Porsche 911 for free?

You can check MOT history free on GOV.UK, which shows past test results and advisories. What it won’t show is outstanding finance, write-offs or theft markers, which are the things that actually cost you money after you’ve bought. Our full check adds all of that for £7.49, using Experian data.

Is a Porsche 911 HPI check worth it?

HPI is one brand of car check. Our check uses the same Experian data covering finance, stolen, write-off and keeper history, plus MOT analysis and known 911 faults that HPI doesn’t include. At £7.49 it’s typically less than half the price of an HPI check.

What does a Porsche 911 fail its MOT on?

The most common MOT failure on the 911 is emissions failure. 12.3% of 911 models fail overall, based on 163,980 tests. Checking a car’s full MOT history before buying shows you recurring problems the seller might not mention.

More on the 911

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Finance, stolen, write-off and owner history data provided by Experian. MOT data from DVSA. Known problems from GetCarWise analysis. Updated October 2026.