I was wondering what is the first thing that wears out in the engine? do you have to worry about the piston rings or the springs/retainers/valves? Or is there something else?

 

Or at least what would wear out that would hurt efficiency the most?

 

I would guess the rings but luckily, I cannot speak from experience @ 16k mi.

 

I just passed the 95k mark. So I want to see what's coming up for me. I don't expect anything to actually break but weat out.

p.s. That's 95k miles like ... and this

 

In terms of hurting performance, I would say rings and valve seats. In terms of oil consumption, valve seals followed by valve guide. In terms of material fatique, I don't have enough experience on the S in that regard (which can be a good thing ) to say.

 

Only thing I'm worried about is a cracked valve retainer--and all the trouble that happens when one fails.

 

Has anyone had a failed valve retainer?
I remember that a lot of the valve design mirrors what they used in the Indy(Champ) car engines when Honda dominated the series in the late 90s.

I had a recent short block change and valve seals change to fix an oil consumption problem. I am not sure if they replace the valve retainer and guides?

 

No (or too few to notice) reports of obvious wear issues. Failures that could be wear related include a number of spun bearing reports and a number of valve retainer failures.

 

Purely from an efficiency perspective, your valve seats will wear out first. If anyone remembers Mark Donahue, one of his "Unfair Advantages" that he used was to have a valve job ONLY done on his race engines. What he found was that once the rings were seated to the cylinders, there was less friction, and that he could gain extra horsepower by doing just a valve job.

So, if you're looking to recover some hp, or mileage, a valve job would be the place I'd start first. BTW, Donahue was a mechanical engineer, who used his engineering skills to increase his competitiveness.

 

Yeah, but Mark raced thirty years ago and valve seat materials have improved (hardened seats became common once unleaded gas was mandated). I have seen alot of things wear out before valve seats in current cars.