[arthrodriver]

I don't own a Boxster, but am considering an older one, expecting to overhaul/mod the engine. I have read many of the posts and also seen a youtube hosted by a bearded uncle type who assumed the know-all, final say posture (good watch).His summary (if I got it right) is that the IMS bearing failure (early/late...I don't know) arises from corrosion (my words). Mechanism: oil collects in the shaft tube and cannot exit. It becomes "rancid" (his words .I think)and becomes corrosive. The seals fail and the ?acidic? goop attacks the balls and races. The bearing wobbles and fatique sets in on the shaft. The fix...pressurized oil lines under gallery pressure constantly clean and lubricate the new bearing. Problem solved. I write this in my words because I don't think I saw this explanation before. So his statement is that although grease is the normal lubricant for ball and rollers, engine oil is the fix for the replacement bearings?

Next, Although the engine shops show broken parts (like the crank above) they do not volunteer non destructive test findings (magnaflux, zyglo etc) to explain. Finally for the person above asking about valve guide slippage. IMO this can be due to incorrect press fit tolerances (guide too small, guide hole too big) or to overheated aluminum head ,or improper installation. Out around 350F aluminum creeps (gets soft)and cannot hold onto guides and seats.

Hope this evokes more info. I know it's out there. These threads are very much like the ones on another site. Mercedes M 156 V8 (many models, but especially C63 AMG) where headbolts break. Those engines are$42K and Mercedes' warranty and mea culpa position is the same as Porsche. The owners there have the same nightmares and angst. Unlike the Boxster engines, most M 156's can be repaired , range $5K - $15K.