How to avoid Porsche Bore scores 

Automotive engines contain a large number of components that are made of aluminum. In your modern water-cooled Porsche engine, these are also the pistons and cylinders. Aluminum is lightweight and versatile, but it also has its limitations. For decades, Porsche used durable Nikasil plating for the wear surface of the aluminum cylinders, but in Boxster, Cayman and 911 engines, Porsche chose to use hypereutectic Lokasil and Alusil engines instead. For this reason, your Porsche may experience bore scores or cylinder bore scores over time.


Scoring Porsche cylinder bores occurs in engines with Lokasil and Alusil engines when there is a breakdown in the aluminum-silicon (Al-Si) cylinders. When the required iron-clad piston coating fails or there is insufficient exposed silicon particles on it. the surface of the aluminum cylinder bore to support the formation of an oil film, accelerated wear will occur on the pistons, rings and cylinder walls. As the pistons and rings move up and down the cylinder, wear debris is dragged through the bore, causing the cylinder bore to rupture.


Certain models are more prone than others to scoring Porsche cylinder bores. with Porsche 911 the 3.6 and 3.8 liter M96.03, M96.05 and M97.01 engines and Porsche Cayman in 3.4 M97.21 engines are most common; Below are all models that may experience this bore scoring problem:

  • Porsche 996
  • Porsche 997
  • Porsche 987
  • Cayman
  • Bore Score Boxster Bore Score (3.4 M97.22 engine only)

Keep in mind that for an engine that has traveled 100.000 miles, each piston went up and down on average more than 300 million times, leading to serious damage and possibly even engine failure if the required preventive maintenance was not performed. The reason that taking steps to prevent the scoring of bores by Porsche is so important is that it can have very negative impacts on your car's performance and engine life. As the score deteriorates, the cylinders lose their ring seal and harmful contaminants get into your oil as it bypasses the piston rings. Those contaminants can then be spread to all the lubricated components in your Porsche's engine, ultimately leading to catastrophic damage in the worst case scenario.


The question is, how can you prevent bores from being scored on your Porsche Boxster, Cayman or 911 engine? We've put together a few steps you can take to extend engine performance and avoid bore scores.

  • Borescope your cylinders – Have your cylinders scoped for scoring bores. It is an excellent idea to know the condition of the cylinder bores. This is especially important if you are in the market to buy a new Porsche.
  • Check your fuel setting and test for vacuum leaks – A Porsche technician with the appropriate diagnostic tools should be able to check the fuel setting values ​​to ensure they are within specification. A bad mass airflow sensor or oxygen sensors can also lead to too much fuel, flushing out cylinders and leading to bores, so these components, along with the AOS and associated vent lines, should also be replaced as part of preventative maintenance to ensure that your engine is running correctly. Vacuum leaks can also cause your engine to run rich, so having the engine smoke tested for leaks is highly recommended.
  • Buy high quality gasoline – Choose a Top Brand supplier or ethanol-free premium fuel for your Porsche to keep your fuel injectors as clean as possible. Dirty injectors can damage the lubrication of cylinders and pistons, leading to excessive wear.
  • Maintain your fuel injectors – Use a bottle of Driven Injector Defender every other fill up. We recommend that you replace your fuel injectors preventively every 100.000 miles to avoid the chance of leaking injectors flushing your cylinders, which can lead to bore scoring. It is not recommended to have your original injectors cleaned instead always replaced with new ones.
  • Install a low temperature thermostat – A low temperature thermostat opens earlier and stays open, while the original factory thermostat can continue to open and close during normal operation, allowing coolant to bypass the radiators and create hot spots in the engine.
  • Start slow until warm – Never let your Porsche engine idle to warm it up as the rich mixture can wash out cylinder bores during a cold start, as can a bad injector. It is important to start driving immediately, but keep the engine speed below 3000 rpm and do not run the engine at full throttle until the engine is at full operating temperature.
  • Change the oil at the recommended intervals – It is important to change your car's engine oil every 6 months or 8.000 kml, preferably with Driven DT40 or DI40, as these oils are formulated with elevated levels of Moly additives that most oils do not have, which in turn helps to protect the cylinder walls. If you track your car, drive short distances, or use the engine in cold climates, you may need more frequent oil changes. Doing so will keep the oil free of contaminants that could damage the Porsche cylinder bore.
  • Don't neglect your filters – Make sure to change your engine oil filter every time you change the oil of your Porsche with a quality oil filter. Consider LN Engineering's spin-on oil filter adapter and add a Filter Mag to improve filtration and make oil changes easier. Remember to replace your air and fuel filters as recommended by Porsche, only with genuine or OEM filters.


If you already have a bore scoring with your Porsche, we can help you. Starting with the Nickies cylinders with new pistons and rings, we can supply all the parts you need to rebuild and upgrade your engine to prevent future failures while maintaining the performance and reliability of your Porsche Boxster, Cayman or 911 vehicle significantly.


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