[Chuck Jones]

Interesting question....and one that I researched fairly extensively when I bought my 99 996. The answer is all over the place....some claiming early failures, others praising the longevity of the engines. It appears that there were some lots that were prone to failures...the most common being intermediate shaft failures, intermix either thru failure of a "D" shaped piece from between the cylinder walls, or pourous blocks that allowed the oil and coolant to intermix.

I found myself getting overly anxious over what seemed to be numerous reports of failures, but then I had to remember that there are literally thousands of these cars out there, and you only hear of the failures. What actual percentage of the total numbers actually failed? To some degree Porsche made it very difficult to make any sort of determination by their policy of replacing the engines that failed under warranty rather than rebuilding them....so the actual "autopsy" to determine the cause was seldom known.

After the warranties ran out, more and more were being rebuilt by well known rebuilders such as the Auto Farm in England....and the failed intermediate shafts, rear main seal failures, and intermix issues have been published....however exactly what the real percentages of these failures are in the grand scheme of the thousands produced is still a best guess scenario. I do know that the Auto Farm is "frightfully busy" rebuilding engines and would be a great place to contact to ask what they most frequently see, and how often.

I was always happy to see the folks who would publish their 100K + mileage figures becasue it reinforced my belief that they didn't fail as frequently as some would lead to believe.

Since I've moved into a 3.6L engine in the TT, I find that I have few if any previous concerns over the longevity of the engine.