lex_gs

63 , finally had enough money to own a 996.

As a recent new owner of an '03 C4 cab I was a little disturbed to hear about engine failures particularly cracked heads and cylinder walls. My background is engineering so I was thinking about what would cause these failures. Some engines go over 100K miles and then have failures so they are probably not caused by manufacturing defects.

These failures brought to mind some advice I heard years ago about never running an engine WOT until it has reached operating temperature. There would be a huge temperature differential between the combustion chamber walls and the water jacket of a cold engine under WOT conditions. Could this stress cause the wall to crack like pouring hot water into a cold glass?

I have decided to be very careful about slowly running the engine up to operating temp before having some fun. Can't do any harm and it may prevent a failure.

I worry about going 15K miles between changes especially when you are not driving a lot of miles per year. I do mine every 5 - 6 K miles. Also decided not to use Mobil 1 any more because of the reduction in ZDDP. Next change I will go to Castrol Syntec 5W -40 which at least has an SL rating. I would stay away from any SM rated oils like Mobil 1 in a pre-2004 engine.

Nothing to worry about. Seems like all 996's have this problem. My 2003 C4 has the same smell like rubber burning. After some research on the web I found that this is caused by tiny pieces of rubber that wear off your tires or is picked up from the road and then thrown against the mufflers which are right behind the rear wheels and are very hot.

Check out Mercury Insurance Group extended warranty. I have them for my 03 C4 cab. So far over $5K of repairs covered with no problems.