With all the talk about proper break-in, frequent oil changes, etc, I wonder if anybody on this board has ever had a mechanical failure clearly related to improper break-in procedures, too many months / miles between oil changes, etc? My bet is "no", but if I'm wrong we might all learn something from the events and the causes.

Examples would include excess wear (e.g. piston or bearing knock), poor running traced to compression loss, excessive oil consumption etc sufficient to require rebuilding.

If you've had one, what was it? At what mileage and age? What caused it? How do you know the cause? Do you have the entire service history for the car?

 

7000 mile without changing oil, not a problem. just my ...... gas

 

That would be a tough case to prove. I've seen pictures of a BMW that went 30,000 miles before its first oil change. The tech said the car came in sputtering and practically stalling, he had to take the oil filter out with a rag and vacum because it was basically degraded into a papery sludge. The oil came out thick and black. They actually decided to drain the oil, put new oil in, run it for a few miles, then change it again. Guess what, the car ran absolutely fine from that point on. These kind of damages may not truly come to the surface for many many more miles or years.

The point is that you'd be hard pressed to get a tech to admit that a car was damaged due to break in or oil change intervals. Poor or uneven compression can be due to a number of things, not just what you mentioned. To further convolude the issue, you're talking about a performance car, the Z is driven with more "spirit" than most cars so engine wear could be due to something as simple as romping the **** out if it for 2 years. just my .02

 

If we find that 25 people who didn't believe in oil changes all threw a rod in the first 20k, the association is probably not coincidental.

I agree with you, though - I bet there aren't any such failures out there. And if that's true, why make a big deal out of "break in" etc? My point here is to either demonstrate that it doesn't really matter much how you break in your engine, how often you change your oil etc or to identify the cause of failure if there seems to be one. I'm with you - it's almost certainly of no consequence, at least in the first 100k+ miles.