oil change effect on IMS bearing

I don't know the real cause, but having changed a number of these bearings, I've never seen a broken or damaged seal on the Porsche original bearings. The new bearings are either one or two row (depending on originals makeup), open cage and ceramic balls. Thus they are open to the crankcase oil. You MUST use the Porsche tools to properly install the bearings. Hope this helps.

The supplied grease seals are only rated to 250F temps, which these engines see regularly. The lip ends up getting hard and brittle. At that point, they fail to seal. The grease is washed out of the bearing and the seal then limits the exchange of engine oil. The simplest solution is to eliminate the seal as the IMS is submerged in oil with the IMS being at the bottom of the engine, which is wet sump (not dry sump). With regards to oil change intervals, the factory intervals are too long for how most of these cars are driven. 6 months or 5,000 miles is best for most people.