• All Engines
• M48.00
• M48.01
• M48.50
• M48.51

• The plastic coolant pipes under the intake manifold very commonly burst – Porsche released an upgraded aluminum part which is much stronger
• There have been reports of bore scoring. It is unclear if this only effects MY03-04 vehicles, or all vehicles with this engine. A borescope inspection should be mandatory as part of a PPI, and scoring usually will manifest symptoms such as excessive oil consumption, smoke from the exhaust, or a loud ticking noise. There are several theories about why this happens, but none of have been confirmed:
  • Overheating due to failure of the plastic coolant pipes (described above), which causes the engine block to warp.
  • Taking short drives without allowing the engine to run at normal operating temperature for long. This means the condensation that forms while the engine is warming up does not burn off, and eventually mixes with fuel and oil that leak past the piston rings when the engine is cool. The ensuing mixture is acidic and causes damage to the cylinder walls.
  • Driving the vehicle hard before the engine has a chance to get to operating temperature, which makes the pistons and the engine block expand at different rates as they warm up and causes the pistons to come into contact with the cylinder walls.
  • Porsche incorrectly believed that the engine block – which was made out of Alusil – was strong enough that it didn’t require cylinder liners. The M48.50 engine didn’t suffer from bore scoring because it had more oil spray, and therefore the pistons ran cooler than in the M48.00 engine – which meant they didn’t expand as much within the cylinder walls and rub against them.

• Porsche Cayenne S (9PA 955)

• Upper front coolant pipe can slip out of housing due to a glue failure
• Engine rear coolant crossmember to both cylinder banks can slip out due to glue failure. Symptoms are a coolant leak coming from the rear of the engine. Fixing it usually requires removing the engine. An updated part was released which is threaded.
• High pressure fuel pump
• Vacuum pump can fail, causing oil to get into the vacuum lines and damage servos under intake – symptoms include a CEL and evap system failure

• Porsche Cayenne GTS, S (9PA 957)

The M48.50 is significantly less likely to experience bore scoring than the M48.00, although it is still possible.

• The plastic coolant pipes under the intake manifold very commonly burst – Porsche released an upgraded aluminum part which is much stronger
• Oil may leak from the pressure hose

• Porsche Cayenne Turbo, Turbo S (9PA 955)

• Porsche Cayenne Turbo, Turbo S (9PA 957)