Audi Broken Oil Control Rings - Why???

[PeterPolyol]

Originally Posted By: SonofJoe
I think I'm right in saying that this was the first high performance production engine to feature both a turbo and direct gasoline injection so it was pioneering stuff.

Mazda DISI 2.3T circa 2005; shipped to all markets, used all fuels/grades, 5w30 oil, zero (0) ring problems.

 

[wemay]

 

[SonofJoe]

I stand corrected! Mazda clearly launched their 2.3L DISI before Audi launched the TFSI. However I might be forgiven for not knowing this. Here in the UK, the 2.3L DISI was used in the Mazda CX-7. When Google found me a photograph of the CX-7, I thought to myself, 'I don't remember ever seeing one of those before!'. Apparently these small SUV's quickly established a reputation of being inordinately thirsty beasts and never really sold that well until they put a more economical diesel engine in them.

Regarding the issue of oil loss, I found this web page....

http://www.mazdaspeedforums.org/forum/f10/mzr-disi-ringland-failures-140371/

If you move down the page, it shows a picture of a 2.3 DISI piston. Ignore the fact that this piston is missing a huge chunk of the second ring land. This is a modified engine probably where too much boost led to detonation and piston damage. Just look at the oil control ring. It's a bit hard to tell but it looks to me like it's a conventional three piece ring. Also the bottom of the third groove isn't compromised by the hole for the gudgeon pin. How significant this is to preventing oil consumption on the DISI I don't know, especially in the light of JHogan's info on the original TFSI pistons being not wide enough for the bore, but I suspect it didn't hurt.