Porsche vehicles have a number of regular sources for leaking oil. Some of the most common include rear main seal (see below), valve covers, spark plug seals and turbo oil supply line seals. Less common are leaks from the cam seals and scavenger oil pump seals.

Symptom : Oil Drips On Floor Behind Rear Wheels

Valve cover leaks are obvious and fairly straightforward to fix on most models. The valve covers do not have a gasket – instead a liquid gasket sealer is used. The time consuming part is removing the old gasket sealer from the valve cover to ensure a good seal for the replacement.

Symptom : Misfires CEL or Oily Spark Plugs

Spark plug tube seals are also prone to leaking – leaks from the spark plug tube seals can be frustrating. Often, you wont see the oil initially as it’s sealed in by the coil on top of the spark plug. The tube fills with oil and causes misfires by destroying the plug and the coil. If you see oil on a plug or coil, always replace the seals.

The early engines had a plastic tube insert and the later engine features two seals. The upper seal can be replaced when removing the valve cover.  The lower seal leaking is more of an issue and requires removal of the camshafts.