1.8 Liter Turbo
Almost a year ago I was driving with a mixture of 1 ounce to 1 gallon of high octane and gasoline on my 1.8t. New Beetle 2000 (don't know if it has something to do).
And at some point I started hearing the camshaft tensioner rattle from idle until 2700 rpms. I also removed the air filter...