Planning to Buy C6

[r2dmax]

So I have given up my dream of buying a C6 S6 due to what seems to be exorbitant maintenance costs as a daily driver.

But I still want a C6. I DEFINITELY want a Quattro. But I need reasonable reliability. I've been driving Euros for 15+ years so I know they aren't Toyotas. My question comes down to this. What is considered the most reliable Engine/Transmission combo?

• 3.2 Quattro
• 4.2 Quattro
• 3.0T Quattro

I am interested in having good power so the 4.2 is on the radar. Not so much bothered by the 4.2 mpg, but I remember the transmission issues on the C5 4.2. I see people rant about the 3.0T and I'm sure it's a hoot, but as to overall longevity which is going to give the best power and reliability?

[whef21]

I think all the engines are pretty strong overall, in power and reliability, but it all depends on SPECIFICALLY what you buy.... even a good engine will burn your wallet if the previous owner took crappy care of it. Also milage plays an important factor. So I guess to answer your question: they are all pretty good engines, but do GOOD research before you buy, the kinda research you'd do if your daughter announced she has a boyfriend

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[c@@kieMonsta]

My best advice to you is to go through this sub-forum and digest all of the previous posts regarding performance and reliability of each engine. As far as transmission is concerned, you don't have to worry about that because all the engines are mated to a ZF 6-speed tip here in the USA.

[SinCityA6]

I have owned both the 4.2 and 3.0t. I would recommend the 3.0t over the 4.2 for a few of reasons (3.2 is not a consideration):

1. Carbon build up. The FSI 4.2 (2006-2011) are prone to Carbon buildup due to the direct injection design of the motor. Granted, the 3.0t is not free of carbon buildup, but it is much less as the positive pressures generated by the supercharger reduce the amount of blow back coming through the intake valves.

2. Modability. The 4.2 is a torque monster and really has some low end grunt but the 3.0t is a quicker car. I raced a friend in his 4.2 (me in my stock 3.0t) and I walked him. It was not a slaughter, but I pulled on him from jump and just kept increasing the lead. Doing some minor modifications (stage I/II) really makes the motor a beast. I just upgraded to GIAC Stage II and all I can say is WOW!. The car pulls like a freight train from jump all the way up to redline. I am confident in saying I will trounce the V10 S6 without issue (and I love the S6).

3. Timing Chains. All three motors use timing chains sandwiched between the motor and the trans. The issues regarding the 3.2 and 4.2 needing chains/tensionors/guides replaced are well documented in this forum. There is not any (thus far) regarding the 3.0t. I had to have the timing chains/tensionors and guides replaced on my 4.2 at about 100k miles becasue they were streched and rattling. Eventhough the issue was covered by my CPO warranty (long story) the car was down 21 days and the cost (if I was paying) would have been $9600. Not saying that the 3.0t is devoid of this issue, as chains stretch and tensionors/guides wear, but I am at 106k miles and there is no indication of an issue (knocks on wood furiously).

As @ c@@kieMonsta stated, all three motors use the same Tiptronic trans so it is a non issue.

[LINDW4LL]

3.0T is the best by far.

Most reliable.
Fastest.
425+HP when tuned.

[c@@kieMonsta]

1. Carbon build up. The FSI 4.2 (2007-2011) are prone to Carbon buildup due to the direct injection design of the motor. Granted, the 3.0t is not free of carbon buildup, but it is much less as the positive pressures generated by the supercharger reduce the amount of blow back coming through the intake valves.

Fixed

[BKN718]

I thought Audi 3.2L was best engine designed?


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[SinCityA6]

Fixed

Thanks. I thought the FSI came out in 2006 (maybe as a 2007 MY car).

[skylinrcr01]

3.2 has timing chain tensioner issues. Mine are going, new ones are almost $400 in parts, and a PITA to change out. I've heard nothing but good things about the 3.0T though.

[KBRUCE23]

Plus one on the 3.0t kudos, and I also LOVE the c6 s6. I definitely considered it but a good buddy of mine is my service advisor at my local dealership and he told me everything I needed to know. It's a great car if you find one that's been taken care of, and if you can and want to keep up the maintenance. I had the 3.2 in my a5, and it was great but nowhere as peppy as the 3.0t, and the a6 is a heavier car. Get the 3.0t, go stage 2 and don't look back!


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[c@@kieMonsta]

Thanks. I thought the FSI came out in 2006 (maybe as a 2007 MY car).

The 32V FSI 4.2 didn't come out until 2007. That's why you see the '05 and 06 with 335HP while '07 and up have 350HP. The '05 and 06' still utilized the non-FSI 4.2 40V.

I thought Audi 3.2L was best engine designed?


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It's a great engine no doubt, but it has some known issues as some have already mentioned. I happen to have both (3.2 and 3.0T) engines currently and I can tell that Audi learned from their mistakes when they designed the 3.0.

[Kevin1]

I thought Audi 3.2L was best engine designed?


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Just a bit of sarcasm?

[BKN718]

Not at all I was told at time when I was looking at Audi to buy 3.2L engine that is the best engine Audi made.


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[c@@kieMonsta]

Not at all I was told at time when I was looking at Audi to buy 3.2L engine that is the best engine Audi made.


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Well, you were misinformed. It's a great engine, but most definitely not the best Audi engine. Not even the best when it comes to this gen of A6.

[Bigshizzy1]

I'm new to posting on this forum but I have to chime in becuase I love my 2010 3.0T; had it for 2 years now and that would be my absolute recommendation of the 3. Its faster than you think and quicker-ish off the line than the 4.2 becuase its a lighter set-up but of course the -50hp doesn't help it keep up with the 4.2 long. However as other have said there's way more modifications available for the 3.0T motor than any of the others so you can make it much quicker than the 4.2 with the added bonus of being more fuel efficient than the 4.2.

My tip purely from my experience: try to get a 3.0T with a CPO warrant still on it, here's why.
1.If the water pump hasn't been changed by the time you buy the car...odds are it will go. Had mine changed under warranty at 60K. Read a lot about them failing...and mine did; so thankful for the warranty
2. some 3.0T have an oil consumption issue; mine did; got my gaskets changed and "oil pressure management" reprogrammed at 70K and haven't sipped any oil and I am just shy of 81K now....where it was a Qt every 1500. Again....so thankful for the warranty

Good luck in your search!

[Kevin1]

Well, you were misinformed. It's a great engine, but most definitely not the best Audi engine. Not even the best when it comes to this gen of A6.

Very true. Wards named both the 4.2 and the 3.0t in the A6 as one of the best 10 engines in the world several years in a row. It never named the 3.2 to the top ten list. It never even gave the 3.2 an honorable mention. The 3.2 is the ugly stepchild to the the 4.2 and the 3.0t.

[SinCityA6]

Very true. Wards named both the 4.2 and the 3.0t in the A6 as one of the best 10 engines in the world several years in a row. It never named the 3.2 to the top ten list. It never even gave the 3.2 an honorable mention. The 3.2 is the ugly red-headed stepchild of the the 4.2 and ugly stepsister to the 3.0t.

Fixed !!

[rollininstyle04]

I love my 4.2, simple naturally aspirated power and a fantastic exhaust note. Had the 3.0T been in my budget when I got my C6 I probably would have gone that route, but no regrets with the 4.2.

[BKN718]

Thank you for your info c@@kisMonsta the next time I'm in the market to purchase an Audi C6. I'll consider 3.0t engine supercharged.


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[Kevin1]

Thank you for your info c@@kisMonsta the next time I'm in the market to purchase an Audi C6. I'll consider 3.0t engine supercharged.


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You won't regret the switch. Huge improvement!

[s4chiro]

3.0T is the best by far.

Most reliable.
Fastest.
425+HP when tuned.

this^^^. end thread;////

[r2dmax]

I was leaning toward the 4.2 (Exhaust note and overall power out of the box) and my thought was to do a cat-back exhaust for a little better growl, tint and wheels. Not drag racing it, but like having the power when I want it. I like the potential weight savings and efficiency of the 3.0t but it's been hard to find a decent priced 3.0t with decent mileage and records in my price range. I'm looking at a 2007 4.2 with low mileage right now

[FormulaElement]

The 4.2 is a good engine, good power and decent gas mileage. I suggest getting a PPI done by a dealer and a compress and/or maybe a leak down test before committing to any car regardless of year or mileage.

[Fociracr]

This all depends on you're budget. You can get a 3.2l for fairly cheap now. I owned a 05' 3.2l and I had to replace my timing chains, its cost me roughly 600 with tools and parts. The engine it self isn't all that exciting to drive very grampa-ish. I was always told to stay away from the 4.2l pretty much the same reason as 3.2l the timing chain issues, but on the 3.2 you can change the the parts out without having to drop the engine, the 4.2l being significantly larger it sits back further so you'd definelty have to drop the engine as there would be no clearance. As far as the 3.0, i have an S4 with that engine and its miles ahead of the 3.2l, in principal its the same design as the 3.2 but the blower makes it great. It's all what you're budget will allow you the 3.0t is more expensive but if you can swing it, get it.