Catastrophic engine failures?

[PixieVC]

I came across a thread on Audizine (linked here: http://www.audizine.com/forum/showth...pdate-12-03-11 ) regarding engine failure of a catastrophic nature for B6/B7 4.2 liter V8 engines.

They complain about a number of issues, such as broken timing chains (looks like a major architectural change from the RS6 4.2), and issues like broken rods, scorched cylinder walls, and other assorted issues.

Are RS6 engines susceptible to these same maladies, or would the unique handbuilt nature of the engines (and perhaps different design and architecture) play a role in keeping us immune from the issues that are being seen on the B6/B7 4.2 V8s?

Is the RS6 motor known for any sort of catastrophic failure mode different from the S4's 4.2 engines?

[MaxRS6]

Here is a bad story due to wiring harness

http://forums.audiworld.com/showthread.php?t=2817001

[4everRS]

There are some big differences in 4.2's through audi's lineup.

The rs6 has more forged peices in it than the normal units. The block itself is very similar to the rest however. The exhaust valves are sodium filled to take the higher temperatures of the boosted engine. I can't get them now but there are threads on the crank rods and pistons. Not 100% on this, but there were some that said they're not forged and were later proven wrong. I have yet to read about something real bad, like throwing a rod.

As Max said above, that was a bad deal. I have to imagine that there was a CEL or SOMETHING, that could have been a sign.

IMO the real reason why we haven't had more failure is due to the OCD servicing and quality of oil these engines have poured into them.

[mik15]

to be honest it's the first time i hear about engine failure to an RS due to a mechanical failure such as broken rods...i have friends with RS4 who used to really race it hard and didn't have any problems with it, i guess this kind of failures appear because they didn't stick to Audi's maintenance or due to over boosting the power to the point where the internals couldn't take it anymore and this combined with hard races results into mechanical failure which is predictable if this was the case...anyway, i don't think it's quite an easy job to destroy an engine which was designed to be pushed hard, they didn't just built the engine, i am sure it had to pass some serious and rigorous tests before entering into mass production...

[QuattroRS]

Different engine.

I will gladly change my timing belt and rollers every 35k over having that chain behind the engine. Gladly

I guess this means old C5 RS6s, S6s and D2 S8s will be getting more and more valuable. ;-)

I came across a thread on Audizine (linked here: http://www.audizine.com/forum/showth...pdate-12-03-11 ) regarding engine failure of a catastrophic nature for B6/B7 4.2 liter V8 engines.

They complain about a number of issues, such as broken timing chains (looks like a major architectural change from the RS6 4.2), and issues like broken rods, scorched cylinder walls, and other assorted issues.

Are RS6 engines susceptible to these same maladies, or would the unique handbuilt nature of the engines (and perhaps different design and architecture) play a role in keeping us immune from the issues that are being seen on the B6/B7 4.2 V8s?

Is the RS6 motor known for any sort of catastrophic failure mode different from the S4's 4.2 engines?

[PixieVC]

Different engine.

I will gladly change my timing belt and rollers every 35k over having that chain behind the engine. Gladly

I guess this means old C5 RS6s, S6s and D2 S8s will be getting more and more valuable. ;-)

Well this all makes me very glad I didn't pull the trigger on a B6 S4... I very nearly did...

I'm going to just forget about it, and enjoy the car... my mind is set at rest.

[vitalian]

Pixie, although there certainly are many potential weak points on the RS6 (e.g., transmission, torque converter, POS DRC suspension system), it is my understanding that the engine is not one of them. Although anecdotal, the absence of threads regarding catastrophic engine failures on this website seems to bear that out.

One of the members here once told me you could probably drop an RS6 engine out of a second-story window and it would be fine after minor repairs (not that I'm recommending that!!!). Although I seriously doubt that, it does seem that the engines on these cars are pretty solid.

[lswing]

I'm going to just forget about it, and enjoy the car... my mind is set at rest.

I try to do this at least once a week...and then go back to obsessing about something...

[4everRS]

Well this all makes me very glad I didn't pull the trigger on a B6 S4... I very nearly did...

I'm going to just forget about it, and enjoy the car... my mind is set at rest.

Belt = Better

Anyone know what the new 4.0tt uses?

[Chung]

Even thread titles like this make me nervous.

[ttboost]

Just checked both links. Interesting, but not earth shattering. Most of the failures you read about are caused by detonation, which is caused by a crap tune and/or an idiot driver (no offense if you are one) not listening to the signs. If you see a piston that has the top by the ring lands all eaten up = detonation, period.

One guy says he was just driving down the road at 40mph. Yeah, right...

[QuattroRS]

+1

I was going to say those guys should have been using Aces. ;-)

Just checked both links. Interesting, but not earth shattering. Most of the failures you read about are caused by detonation, which is caused by a crap tune and/or an idiot driver (no offense if you are one) not listening to the signs. If you see a piston that has the top by the ring lands all eaten up = detonation, period.

One guy says he was just driving down the road at 40mph. Yeah, right...

[PixieVC]

I try to do this at least once a week...and then go back to obsessing about something...

C'est la vie. I'm a car hypochondriac; I will always default to the worst case scenario for any minor hiccup the car makes - that is usually all in my head anyway. Obsessing over minutiae is a way of life when you're a computer geek... spills into other areas too.

[Chung]

C'est la vie. I'm a car hypochondriac; I will always default to the worst case scenario for any minor hiccup the car makes - that is usually all in my head anyway. Obsessing over minutiae is a way of life when you're a computer geek... spills into other areas too.

I was just telling a few this at beer night as well. I have a small leak and my friends laugh as I freak out. They have now said they are going to follow me around with oil and just make random oil spots below my car to see my reaction.

[papadoc]

Hey, are you related to Brian at BND or something like that? ;-)

+1

I was going to say those guys should have been using Aces. ;-)

[lswing]

Hey, are you related to Brian at BND or something like that? ;-)

I'm pretty sure ACES does not work at all....kidding kidding, here's to being safe with the engine!

[s42ski]

Iswing,

like the old add says - "try it you'll like it". Perhaps finding a user in the area you live in and doing a "butt dyno" test?? I was having difficulty buying the claims of BND as well, then I talked with Brian - who if he is not a chemical engineer, he can talk with one ( I have a friend that works at Chevron and had him on the phone - he now uses BND products!).

I also ran tests on his oil before putting it in the car.

Final bit - just did 75k service - plugs were clean, intercoolers were basically dry. All with BND

[QuattroRS]

Oh gosh can we take all this evidence from deadbeat engineers, physicians, and long term RS6 owners and say Aces is rubbish?

I dont have to pay for your pistons so choose wise.

Iswing,

like the old add says - "try it you'll like it". Perhaps finding a user in the area you live in and doing a "butt dyno" test?? I was having difficulty buying the claims of BND as well, then I talked with Brian - who if he is not a chemical engineer, he can talk with one ( I have a friend that works at Chevron and had him on the phone - he now uses BND products!).

I also ran tests on his oil before putting it in the car.

Final bit - just did 75k service - plugs were clean, intercoolers were basically dry. All with BND