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Porsche · Known Issues

2016 Porsche 911 Problems: 7 Known Issues

2016 model year · 12,500+ owner reports · Updated September 2026

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Issue summary

According to Au7o's analysis of 12,500+ owner reports, the 2016 Porsche 911 has 7 documented known issues, with 3 rated critical. The most serious are Cylinder Bore Scoring (Nikasil Wear) ($8,000-$25,000 repair), Timing Chain Tensioner and Guide Failure ($3,000-$7,000 repair) and Coolant Pipe and Fitting Leaks ($800-$2,500 repair). The most commonly reported issue is Rear Main Seal (RMS) Oil Leak with 3,800 owner reports. Across all issues with published estimates, repair costs range from $150 to $25,000. DIY maintenance guides at au7o.io.

In This Article

  • 911 Engine4
  • 911 Cooling1
  • 911 HVAC1
  • 911 Brakes1
  • Recalls7
  • FAQ
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In This Article

  • Engine4
  • Cooling1
  • HVAC1
  • Brakes1

All 7 Known Issues

Filter:
ALL YEARS202620252024202320222021202020192018201720162015201420132012201120102009200820072006200520042003200220012000199919891986198319821980197819761975197419731972197019681965

When Issues Typically Appear

Cylinder Bore Scoring (Nikasil Wear)
20K-80K
Coolant Pipe and Fitting Leaks
30K-80K
Direct Injection Intake Valve Carbon Buildup
30K-70K
Timing Chain Tensioner and Guide Failure
40K-100K
Rear Main Seal (RMS) Oil Leak
50K-120K
038K75K113K150K mi
Community reported
3,200 owners

On the 2009-2019 Porsche 911, the 991-generation 911 suffers from cylinder bore scoring where the Lokasil cylinder liners develop deep vertical scores, typically on cylinders 1 and 6. This is caused by inadequate oil supply to the cylinder walls during cold starts and short-trip driving. The issue results in excessive oil consumption and eventually requires engine rebuild or replacement.

This issue also affects: Audi S8, Audi A4, Audi A1

Common Symptoms

  • Excessive oil consumption (more than 1 quart per 1,000 miles)
  • Blue or white smoke on cold start
  • Rough idle when engine is cold
  • Metallic rattling from engine
  • Compression test showing low values on cylinders 1 or 6

How to Fix

Engine must be removed and disassembled. Scored cylinders are repaired by installing iron sleeves (LN Engineering Nickies) or replacing the cylinder block. Some owners opt for a used or rebuilt engine. Prevention: always warm the engine fully before spirited driving and avoid short trips.

Owner tips & cautions

  • WarningWhen buying a used 991, always perform a leak-down and compression test before purchase. Bore scoring is extremely expensive to repair and often not covered under Porsche warranty after the initial period.
Typical repair cost:$8,000 - $25,000

Research This Issue

Based on 3,200 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High Confidence3,200 owner reportsLast reported by owners Feb 2026Reviewed Mar 2026
Community reported
1,800 owners

On the 2009-2019 Porsche 911, the 991-generation timing chain tensioners can lose hydraulic pressure, particularly after the car has been sitting for extended periods. This allows chain slack on startup, which can jump timing and cause catastrophic valve-to-piston contact. The plastic chain guides also wear prematurely on high-mileage engines.

This issue also affects: Audi A4, Audi A1, Audi A5

Common Symptoms

  • Rattling noise on cold start for 1-3 seconds
  • Chain slap noise from engine
  • Check engine light with timing codes
  • Rough running after sitting for weeks
  • Metallic debris in oil

How to Fix

Replace timing chain tensioners with updated Porsche parts. On early 991.1 cars, the tensioner design was revised (updated part number). Replace chain guides at the same time. Some shops recommend replacing chains as well if mileage is above 80,000.

Owner tips & cautions

  • WarningIf your 991 has been sitting for more than 2 weeks, do not rev above 3,000 RPM for the first 5 minutes — allow oil pressure to fully pressurize the tensioners.
Typical repair cost:$3,000 - $7,000

Research This Issue

Based on 1,800 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High Confidence1,800 owner reportsLast reported by owners Jan 2026Reviewed Mar 2026
Community reported
3,800 owners

On the 1999-2019 Porsche 911, the rear main seal on the M96, M97, and MA1 flat-six engines is prone to leaking oil onto the clutch and flywheel. The seal hardens over time and the flange design allows oil to migrate past the seal. This is often discovered during clutch replacement or when oil drips appear under the rear of the car.

Common Symptoms

  • Oil drip from bellhousing area
  • Burning oil smell from rear of car
  • Clutch slipping due to oil contamination
  • Oil spots on garage floor near rear axle
  • Visible oil on flywheel during inspection

How to Fix

Replace the rear main seal. This requires transmission removal and is commonly done alongside clutch replacement and IMS bearing upgrade to save labor costs. Use the updated Porsche OEM seal design.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Genuine Porsche 0PB105249 updated PTFE rear main seal

    1999-2008 Porsche 911 996/997 M96/M97 applications after VIN/engine confirmation; 0PB105249 supersedes 99710121200 and 99911349040. Excludes 2009-2019 MA1 engines.

    LN Engineering

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Owner tips & cautions

  • TipAlways replace the RMS when doing a clutch job — the labor overlap saves $1,000+. Bundle with IMS bearing replacement on 996/997 cars.
Typical repair cost:$1,500 - $3,500

Research This Issue

Based on 3,800 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High Confidence3,800 owner reportsLast reported by owners Dec 2025Reviewed Mar 2026
Community reported
2,200 owners

On the 2009-2019 Porsche 911, the direct injection system on 991 engines does not spray fuel over the intake valves, allowing carbon deposits to accumulate on the valve stems and ports. Over time this restricts airflow, causing rough idle, misfires, and reduced power. The flat-six layout makes walnut blasting more labor-intensive than on inline engines.

This issue also affects: Audi S8, Audi A4, Audi A1

Common Symptoms

  • Rough idle that worsens over time
  • Hesitation on acceleration
  • Misfires at low RPM
  • Reduced fuel economy
  • Check engine light with misfire codes

How to Fix

Perform intake valve walnut blasting to remove carbon deposits. This typically needs to be done every 40,000-60,000 miles on DFI engines. Some shops use chemical soak methods as well. Consider installing a catch can to reduce oil vapor entering the intake.

Owner tips & cautions

  • TipInstall an oil catch can (JHM or similar) to significantly reduce carbon buildup on intake valves. This extends the interval between walnut blasting services.
Typical repair cost:$800 - $1,800

Research This Issue

Based on 2,200 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High Confidence2,200 owner reportsLast reported by owners Jan 2026Reviewed Mar 2026
Community reported
1,500 owners

On the 2012-2019 Porsche 911, the plastic coolant pipes and quick-connect fittings on the 991 generation are prone to cracking and leaking, especially at the connections near the front radiators. The plastic becomes brittle with heat cycling and age. Coolant loss can be gradual and difficult to detect until the engine overheats.

Common Symptoms

  • Coolant level dropping with no visible external leak
  • Sweet smell from front of car near radiators
  • Overheating warning on dashboard
  • Coolant pooling under front bumper area
  • Steam from front wheel wells

How to Fix

Replace cracked plastic coolant pipes with updated Porsche parts or aftermarket aluminum replacements. Inspect all quick-connect fittings and replace any that show signs of degradation. Pressure test the cooling system annually.

Owner tips & cautions

  • TipReplace plastic coolant pipes with aluminum versions from Numeric Racing or similar — they eliminate the cracking issue permanently.
Typical repair cost:$800 - $2,500

Research This Issue

Based on 1,500 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High Confidence1,500 owner reportsLast reported by owners Feb 2026Reviewed Mar 2026

On the 2016-2019 Porsche 911, porsche symptom-based bulletin SY 72/17 (Group 8, 8530) covers the 911 (991) line from model year 2012 through 2021, which includes the entire 991.2 run. The complaint is that the fresh-air fan for the heating/ventilation system simply does not run - no blower on any speed, so no cabin heat, no ventilation and no windshield defrost. Porsche's stated cause is that when air humidity is high and the car has been parked for several days, deposits build up in the fan motor so it can no longer overcome the higher starting torque required and fails to spin up on its own. An NHTSA complaint on a 2017 911 Carrera (ODI 11478877) describes exactly this: the heater/AC fan does not come on after the car has sat for a few days in a humid climate, recurring roughly weekly, with the owner noting the loss of defroster function as a safety concern. The fault is not a blown fuse or a failed resistor, which is where most diagnosis goes wrong.

Common Symptoms

  • Heater/AC blower does not run on any speed setting
  • Problem appears after the car has been parked several days in humid weather
  • No windshield defrost or defog, windows fog up
  • Blower sometimes starts working again on its own after driving
  • No fault light illuminated

How to Fix

Per SY 72/17 the fix is to break the fan wheel loose by hand and then force it to run: lift the cover on the air intake pre-filter until the fan wheel can be reached, move/free the fan wheel manually, reinstall the pre-filter cover, then use the PIWIS Tester to run the drive-link activation for the fresh-air fan (Air conditioning control unit, Drive links checks, Heating/ventilation, Activation: fresh-air fan) with an activation time of 200 seconds at 100 percent, so the motor runs at maximum speed for several minutes and clears the deposits. Read out and erase the fault memories afterwards. A battery charger of at least 90 A should be connected during the procedure. Porsche invoices this as labor operation 85304900 'Reworking fan motor' with damage type 1712 'Catches/gets stuck'. If the motor seizes repeatedly, replacement of the blower motor is the durable fix. Because a dead blower means no defroster, treat a recurring case as a visibility safety item rather than a comfort annoyance.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Nissens/ACM 99157392200 HVAC blower motor assembly

    Confirm VIN, steering side and original part number; not the RHD 99157392201 branch.

    Sierra Madre Collection

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$150 - $900

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Aug 2026

On the 2016-2019 Porsche 911, porsche Advanced Technical Information bulletin 2106.1, later reissued as symptom-based bulletin SY 109/21 (Group 4, 4407), covers 911 (991) cars fitted with the central wheel lock (M-no. 478): Carrera GTS, Turbo, Turbo S, GT3, GT3 RS, GT2 RS and Speedster, model years 2014 through 2019, with aluminium alloy wheels and PCCB brake discs. The customer complaint is a clicking noise from the front of the car while turning, typically at low speed. Porsche's stated cause is micro-movement at the interface between the wheel and the brake disc bell, driven by insufficient pretension on the centerlock nut, reduced friction between the contact surfaces, or geometric discrepancies between parts. The micro-movement transfers aluminium from the wheel onto the brake disc bell, where it cold-welds and produces a stick-slip effect that is heard as clicking as the wheel rotates. This is specific to centerlock-equipped 991s - five-lug Carrera and Targa cars without M-no. 478 do not have this interface and are not affected. Porsche explicitly states the noise does not impair braking performance or safety and does not constitute a defect, but it is commonly and expensively misdiagnosed as a wheel bearing, CV joint or brake pad fault.

Common Symptoms

  • Clicking noise from the front of the car while turning at low speed
  • Noise absent when driving straight
  • Clicking returns some time after a wheel-off service
  • Aluminium transfer or scuffing visible on the brake disc bell when the wheel is removed

How to Fix

Do not start by replacing bearings or pads. Follow the bulletin sequence: remove both front wheels and both front brake discs, then visually inspect the brake discs, wheel hubs, wheel cones (the centerlock nut seat in the wheel), centerlock nut assemblies, wheels and drive pegs for damage, replacing anything damaged. Then work through the three causes in order - check the central wheel lock and its preload, check the contact surfaces of rim, brake disc and wheel hub for loss of friction, and check the rim, brake disc and wheel hub for geometric discrepancies - applying the corresponding remedy for whichever test fails. Transferred/cold-welded aluminium on the disc bell must be cleaned off. Correct torquing of the centerlock nut to specification at every wheel removal is the main preventative; Porsche notes the centerlock design came from racing and that road-car hub geometry demands the specified procedure be followed exactly.

Typical repair cost:$300 - $2,500

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Aug 2026
NHTSA Recalls7 recalls

AIR BAGS: AIR BAG/RESTRAINT CONTROL MODULE

Porsche Cars North America, Inc. (Porsche) is recalling certain 2016-2017 911 and Boxster, 2016 Cayman and Panamera vehicles. The air bag Electronic Control Unit (ECU) may have a defective power supply capacitor that can result in air bag deactivation or inadvertent deployment of the air bags.

Campaign #19V53300017/07/2019

AIR BAGS

Porsche Cars North America, Inc. (Porsche) is recalling certain 2018 718 Boxster, Boxster S and Boxster GTS, 718 Cayman, Cayman S and Cayman GTS, 911 Carrera, Carrera T, Targa 4 GTS, Carrera 4, Carrera S, Carrera 4S, Carrera GTS, Carrera 4 GTS, Carrera Cabriolet, Carrera S Cabriolet, Carrera 4S Cabriolet, Carrera GTS Cabriolet, Carrera 4 GTS Cabriolet, Targa 4, Targa 4S, Turbo, Turbo S, Turbo S Exclusive Series, Turbo Cabriolet, Turbo S Cabriolet and GT3 vehicles. The side air bag impact sensors may not have been properly tightened to the vehicle.

Campaign #19V17900006/03/2019

AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE

Porsche Cars North America, Inc. (Porsche) is recalling certain 2016 911 GT3 RS and 911 R vehicles and 2017 911 Carrera, 911 Carrera Cabriolet, 911 Carrera 4, 911 Carrera 4S, 911 Carrera 4S Cabriolet, 911 Carrera S, 911 Carrera S Cabriolet, 911 Targa 4, 911 Targa 4S, 911 Turbo S, 911 Turbo S Cabriolet, 718 Boxster, 718 Boxster S, 718 Cayman and 718 Cayman S vehicles. The passenger frontal air bag inflator initiator may fail to ignite during a crash.

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Frequently Asked Questions

What are the most common Porsche 911 problems?

According to Au7o's analysis of 12,500+ owner reports, the 2016 Porsche 911 has 7 documented issues. The most frequently reported are: Cylinder Bore Scoring (Nikasil Wear), Timing Chain Tensioner and Guide Failure, Coolant Pipe and Fitting Leaks. Of these, 3 are rated critical and should be addressed promptly.

Is the Porsche 911 reliable?

The 2016 Porsche 911 has 7 known issues documented across 12,500+ owner reports. 3 issues are rated critical: Cylinder Bore Scoring (Nikasil Wear) and Timing Chain Tensioner and Guide Failure and Coolant Pipe and Fitting Leaks. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Porsche 911 problems?

Repair costs for known Porsche 911 issues range from $150 to $25,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Cylinder Bore Scoring (Nikasil Wear), typically costs $8,000-$25,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2009-2019 Porsche 911 Cylinder Bore Scoring (Nikasil Wear)?

The 991-generation 911 suffers from cylinder bore scoring where the Lokasil cylinder liners develop deep vertical scores, typically on cylinders 1 and 6. This is caused by inadequate oil supply to the cylinder walls during cold starts and short-trip driving. The issue results in… Repairs typically run $8,000-$25,000. Severity: high.

What is the 2009-2019 Porsche 911 Timing Chain Tensioner and Guide Failure?

The 991-generation timing chain tensioners can lose hydraulic pressure, particularly after the car has been sitting for extended periods. This allows chain slack on startup, which can jump timing and cause catastrophic valve-to-piston contact. The plastic chain guides also wear p… Repairs typically run $3,000-$7,000. Severity: high.

Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

Data sourced from 12,500+ owner reports, NHTSA recalls, TSBs, and automotive forums.

Recalls
7
  • FAQ
  • Campaign #17V13400002/03/2017

    VISIBILITY:WINDSHIELD

    Porsche Cars North America, Inc. (Porsche) is recalling certain 2017 911 Carrera Cabriolet, 911 Carrera 4 Cabriolet, 911 Carrera 4S Cabriolet, 911 Carrera S Cabriolet, 911 Targa S, 911 Targa 4S, 911 Turbo Cabriolet, 718 Boxter and 718 Boxter S vehicles. During manufacturing, the windshield may not have been properly bonded to the vehicle, allowing it to detach in a crash. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 212, "Windshield Mounting."

    Campaign #17V13500002/03/2017

    LATCHES/LOCKS/LINKAGES:HOOD:LATCH

    Porsche Cars North America, Inc. (Porsche) is recalling certain model year 2014-2015 Porsche 911, Boxster, and Cayman vehicles manufactured May 7, 2014, to September 23, 2014. The front hood upper lock components were not manufactured to specification and may fail to securely latch the vehicle's hood during operation.

    Campaign #14V69800004/11/2014

    + 2 more recalls. Check all on NHTSA.gov

    Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

    What is the 2012-2019 Porsche 911 Coolant Pipe and Fitting Leaks?

    The plastic coolant pipes and quick-connect fittings on the 991 generation are prone to cracking and leaking, especially at the connections near the front radiators. The plastic becomes brittle with heat cycling and age. Coolant loss can be gradual and difficult to detect until t… Repairs typically run $800-$2,500. Severity: high.

    What is the 1999-2019 Porsche 911 Rear Main Seal (RMS) Oil Leak?

    The rear main seal on the M96, M97, and MA1 flat-six engines is prone to leaking oil onto the clutch and flywheel. The seal hardens over time and the flange design allows oil to migrate past the seal. This is often discovered during clutch replacement or when oil drips appear und… Repairs typically run $1,500-$3,500. Severity: medium.

    What is the 2009-2019 Porsche 911 Direct Injection Intake Valve Carbon Buildup?

    The direct injection system on 991 engines does not spray fuel over the intake valves, allowing carbon deposits to accumulate on the valve stems and ports. Over time this restricts airflow, causing rough idle, misfires, and reduced power. The flat-six layout makes walnut blasting… Repairs typically run $800-$1,800. Severity: medium.

    What is the 2016-2019 Porsche 911 Fresh-Air Blower Motor Seizes After the Car Sits - No Heat, Vent or Defroster?

    Porsche symptom-based bulletin SY 72/17 (Group 8, 8530) covers the 911 (991) line from model year 2012 through 2021, which includes the entire 991.2 run. The complaint is that the fresh-air fan for the heating/ventilation system simply does not run - no blower on any speed, so no… Repairs typically run $150-$900. Severity: medium.

    What is the 2016-2019 Porsche 911 Clicking From the Front Axle on Centerlock-Wheel Cars - Wheel Material Cold-Welding to the Brake Disc Bell?

    Porsche Advanced Technical Information bulletin 2106.1, later reissued as symptom-based bulletin SY 109/21 (Group 4, 4407), covers 911 (991) cars fitted with the central wheel lock (M-no. 478): Carrera GTS, Turbo, Turbo S, GT3, GT3 RS, GT2 RS and Speedster, model years 2014 throu… Repairs typically run $300-$2,500. Severity: low.