First Gen Porsche Cayenne V8 Cylinder Scoring
If you are considering a first-generation Porsche Cayenne, you should be aware of the potential issue of cylinder bore scoring in the V8 955 engine. This problem is most common on naturally aspirated 4.5-litre cars. It is believed that turbocharged versions of the engine are less likely to suffer from this issue, primarily because the turbocharged engines use an Alusil block, better bore clearance, different pistons, and oil squirters that increase oil lubrication, while the naturally aspirated engine uses a less durable Lokasil aluminium cylinder wall coating.
Cylinder bore scoring can present several symptoms. These include a noise similar to a hydraulic lifter issue, one tailpipe being sootier than the other, and increased oil consumption, though this may be difficult to confirm during a short test drive or inspection. Aluminium debris may be found in the oil filter and engine oil sump. In severe cases, the excessive oil consumption can lead to the aging of O2 sensors or cat failure. Misfires and a CEL are also symptoms.
For vehicles produced from 2008 onwards, they are less susceptible to cylinder bore scoring due to refinements in the V8 engine’s design and manufacturing processes. However, cold weather and long periods of non-use are believed to increase the chances of this problem occurring.
Because the symptoms of oil consumption, misfires, lack of power, and a CEL are shared with other problems, cylinder bore scoring can often be misdiagnosed.
If you suspect a Cayenne you are looking at has this issue, you should not purchase the car. Fixing the issue could set you back anywhere from US$10,000 to $30,000, with experienced Porsche specialists being at the higher end of that range, and Turbo rebuild costs tending to be more expensive. A cheaper alternative is to replace the bad power unit with a used one, though finding the history of that engine would be nearly impossible. If you do buy one of these cars, regular servicing with Porsche-approved A40 spec engine oil is the main thing to watch out for.
Read the full guide: First Gen Porsche Cayenne
