IsItAGoodCar
Reliability Guide

Common Problems with the
2005 Porsche 911 (997)

The 2005 launch of the 997 was a return to form for the 911, bringing back the classic round headlights and introducing a much higher quality interior. It was a massive sales success but retained the M96/M97 engine architecture and its associated risks.

What changed for 2005

  • •Debut of the 997 generation, returning to classic round headlights.
  • •Launch of the Carrera (3.6) and the new Carrera S (3.8).

Common MOT watch-outs

  • !Suspension knocks from worn front top mounts or lower control arms.
  • !Corrosion on exhaust backboxes and manifold bolts.
3
Known Issues
2
Serious
1
Moderate
0
Minor

All Known Issues

Bore Scoring (Gen 1)

SeriousEngine

The Lokasil/Alusil cylinder liners degrade, causing the piston to score the walls. Eventually requires a full rebuild.

Est. Repair Cost: £8,000–£12,000 (rebuild)
Warning Signs:

Ticking noise at idle, High oil consumption, Sooty left exhaust tip

What to Inspect:
  • Get a specialist bore scope inspection
  • Listen for a rhythmic "slap" when warm
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IMS Bearing (997.1)

SeriousEngine

While the 997.1 uses a larger bearing than the 996, early 2005 models still use the smaller bearing. Later 997.1 cars use a larger, more robust bearing but failure is still possible.

Est. Repair Cost: £1,500–£2,500 (preventative)
Warning Signs:

Metal debris in oil filter, Oil leak near rear main seal area, Sudden engine failure

What to Inspect:
  • Ask if IMS upgrade has been fitted
  • Check if car is a 2005 model year (highest risk)
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Cracked Ignition Coil Packs

ModerateEngine

The coil packs on 997 engines are prone to cracking and failing, causing misfires. A relatively inexpensive fix but common across all variants.

Est. Repair Cost: £200–£400
Warning Signs:

Engine misfire, Check engine light, Rough idle, Hesitation under acceleration

What to Inspect:
  • Scan for misfire codes
  • Inspect coil packs for visible cracks
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Buying Tips for 2005 Porsche 911 (997)

  • ✓The 3.8-litre Carrera S engines (M97) are highly susceptible to cylinder bore scoring; a bore scope inspection before purchase is absolutely critical.
  • ✓Check the IMS bearing status, although larger bearing versions (post-2006) are less prone to failure but harder to replace.
20042006–2008
Check a 2005 Porsche 911 (997) by Registration