Steppenaudi

The Audi dipstick for the 2013 2.0 TFSI IS PN#: 06J-115-611-E. I've checked this directly with the dealership shop dipstick. It reads correctly.

MP4.2+6.0

a new/rebuilt short block in reality. Dealers don't typically do internal engine work below the major subassembly level. Net, that would usually be a good thing since a factory rebuild facility will have all the tooling, QC, etc.

Redd

dipstick- Thanks, steppan.

Oil consumption-
I could see new rings, but rings and pistons?? That almost sounds like they screwed up on the manufacturing spec for the pistons, so they need to be replaced. What aren't they saying, that requires the pistons to be replaced as well as the rings?

madcrazy10

Yeah,I don't know what else to ask. I'm just going by what the service advisor is telling me. He said new rings & pistons so that's what they are going to do. I'm not complaining as I'd prefer them do this rather than nothing and tell me to just add oil when it asks.

Bob Petruska

The dip stick P/N listed is correct.

Now how much do you know about engines (rings and pistons)? I have built quite a few engines in my life and this is my take on why previous Audi 2.0T engines consume oil. First they were using the lightest tension rings that they could get away with to increase fuel milage. Second, I came across an Audi video that showed the cylinder wall finish was super smooth using a laser to perfrom the operation. Yes, the weak rings and super smooth cylinder wall finsh reduced friction and improved fuel milage ever so slightly, but at the expense of a poor ring to cylinger wall sealing interface allowing oil consumption. No cylinder wall is bored perfectly round, and even if it was when you bolt the head on it distorts the roundness. All the engines I have ever seen and the ones I built have a cylinder wall with a 30-45 degree cross-hatch micro finish (not smooth as Audi does) that acts as a file to conform the rings to the irrigularities of the non-round cylinger bore. The ring filing takes place during break-in and eventually the cylinder wall cross-hatching disappears with the rings conforming to the cylinder wall bore shape. This creates the best ring sealing possible and mimimizes oil consumption. When the dealer installs new rings he most likely is honing the cylinder was with the cross-hatching, using higher tension rings. Many owners that have new rings installed have indicated that their fuel milage decreased initally and then went back to normal. This is most likely due to the increased friction caused by the cross-hatching that eventually wears away.

I would not worry about getting new rings and pistons, I would worry about who is doing the job and his skill. I have seen some engines pulled at dealers, turned upside down with anti-freeze running thoughout the engine, they pulled the heads and oil pan, replaced the rings and pistons in the dirty engine, started it up with new oil and that was it. Yes the engine will run fine initally but down the road a month later, a year later, the owner wonders why is the engine dieing now.

Redd

Bob-
"Now how much do you know about engines (rings and pistons)?"
Last time I rebuilt an engine it was an Onan industrial generator and lasers were something that really really big corporations might be able to buy

"the lightest tension rings that they could get away with"
Makes sense to me. Of course there's a difference between "sufficient" and "excessive" in any engineering decision, and it sounds like someone didn't run a complete testing regime on that one.

"All the engines I have ever seen and the ones I built have a cylinder wall with a 30-45 degree cross-hatch micro finish" Yup. Of course what we have seen will always represent last years' technology, and things tend to change. Maybe super-smooth will be made to work. Kinda like the way Chevy copied Porsche in the 70's when they built the aluminum black Vega engine and stuck in a 210F thermostat to create less cylinder wall quench and higher power. Except, Porsche owners apparently are aware that you need oil and water to cool an engine, Chevy owners, not so much. So Chevy's faithful copy resulted in mass engine failures. Oops.

All of which still doesn't explain why new pistons would be needed. Maybe there are issues with the way that rings seat into the pistons, and these days conservative engineering says to replace them as sets? Instead of just replacing rings? Or the new rings are profiled differently on the side that faces the pistons, as well, making that more of an issue?

I fully share your thoughts as to the competency of anyone doing a major engine job. Never met a shop that didn't press the mechanics to beat "book time" and if they're just getting paid warranty rates...What can you do? Maybe insist on an extended engine warranty, and still consider selling the car before that's up.

Steppenaudi

A thought - new pistons are needed because the dealer plans to bore out the cylinder walls to get a fresh surface, and ever-so-slightly larger pistons will be needed.

Bob Petruska

but doubt that as the dealer can't do it unless he has a boring mill and I doubt that. Now they may hone them, but there is a later new ring/piston P/N for you engine.

As stated above most likely different rings that take different piston ring groves. There have been a few owners repoting very badly scored cylinder walls from broken rings/pistons. Audi probably beefed up both the rings and pistons.

Remember the Audi engine design team runs these engines in the shop to destruction and see what fails. I'm sure they seen the oil consumption issue before the design ever hit production. Again Audi states in the manual that 1 qt. per 1200 miles oil consumption is within the design specs.

Bob Petruska

Looks like every 6 months since 2011 the ring/piston P/N's changed. They just changed the P/N's again in August 2013, that's scary as something must have caused some concern and needed another change. I have a June 2014 Q5. So I have the older MY2014 rings/pistons but I don't burn any oil.