Porsche Turbo
The 4.5L biturbo in the Turbo variant with up to 521 hp in the Turbo S is technically related to the M48.00, but in a sportier context. The sound is typical V8 biturbo thunder, the pull on the motorway is impressive even by today's standards. The weaknesses are the same as the naturally aspirated version, but hit earlier and harder due to turbo stress: plastic coolant lines in the V-valley, Alusil cylinder coating, crankcase ventilation — each of these can become expensive. Anyone buying a 955 Turbo should expect workshop costs and budget for them. As a driving experience the 4.5T biturbo is exceptional for its era.
Power SUV from the first generation
The 4.5L biturbo in the early Cayenne Turbo is an experience — 620 Nm available everywhere, the SUV moves with a lightness that surprises despite the weight. Suspension tuning was good for its era, surpassed by modern standards. But the punch: timeless. Budget for maintenance.
Engine Weaknesses 7
At high mileage the turbo bearings wear out. Oil enters the exhaust stream and repairs are extensive.
Symptoms: Bluish smoke, oil consumption rises, whining noise gets louder
Alusil cylinder coating detaches, pistons tilt and seize. Particularly common with short-trip driving and long oil change intervals. Repair €5,500–23,000.
Symptoms: Knocking from the engine bay that subsides after warm-up, blue smoke, power loss
Crankcase breather fails and draws oil into the intake tract or turbo. In documented cases this led to total engine failure through oil starvation.
Symptoms: Heavy blue smoke, extremely elevated oil consumption, turbo overheating
Improved materials compared to M48.00, but plastic pipes in the valley remain a weak point. Preventive replacement recommended above 80,000 km.
Symptoms: Coolant loss without visible leak, sweet smell
On turbo variants the wastegate actuator solenoid valves can fail. Boost pressure faults and limp mode result.
Symptoms: Power loss, turbo whistle changes character, engine check light
The 8 ignition coils on the V8 fail from heat and vibration. Individual or multiple coils need regular replacement.
Symptoms: Stumbling at idle, misfires, engine check light
The left MAF sensor connector loses its locking tab from vibration. The MAF signal drops out sporadically and mimics other faults.
Symptoms: Stumbling on warm engine, rough idle, sporadic fault codes
Vehicle Weaknesses 9
Air suspension compressor fails through overloading. Most common cause: leaking air bags force the compressor to run continuously. Vehicle sags.
The Cayenne 955 is prone to rust on sills, door bottom edges and rear wings. Stone chips accelerate corrosion considerably. Cavity sealing recommended.
Electronic steering column lock (ELV) engages after a deeply discharged battery. Vehicle can neither be started nor steered.
Design fault with the sunroof drains. Blockage leads to water ingress into the interior. Regular cleaning of the drain channels required.
Propshaft centre bearing wears and causes vibrations. Simple repair, but if ignored, secondary gearbox damage can follow.
Mechanical parking brake seizes in cold weather or corrodes from disuse. Brake cables stretch and need adjustment.
A/C compressor and interior blower fail through age and overheating. Condenser and compressor often need to be replaced together.
Tailgate gas struts lose pressure over time. The tailgate only opens halfway or falls down onto your head while loading.
Plastic trims and foam parts become brittle, fade and creak. Door cards and headliner fabric come loose.
Reports & Tests
257 owner complaints filed with NHTSA (2002–2010). Most reported: Powertrain (54), Fuel System (48), Engine (39).