Hey Everyone,

Looking to buy an older higher mileage A6 in the 2002-2004 range with around 100k miles to have for my wife to drive in the winter instead of an SUV. My question is what engine should I choose, the 2.7T or the 4.2? What are the common problems with each and what should I watch out for? Knowing how I am and the fact that I like to modify everything let me know the pros and cons of modifying these engines. I won't do much to them, maybe a chip, exhaust and intake. I assume the 2.7T will be faster once modified?

thanks for your help

 

In short 2.7t. It's quicker to 60 stock for stock but the 4.2 beats it in the 1/4. If you chip the 2.7 all bets are on the 2.7t

There are lots of topics on the common problems of both engines (a little search) by with 100k make sure the timin belt was done. The automatic tranny in the 2.7 is a bit more reliable IF you stay stock than the stock tranny of the 4.2

 

If you want "reliability" (a oxymoron when talking about Audi), don't chip it. The fact that you are looking at high(er) mileage, you have a choice: worry about turbos (2.7T) or worry about the transmission (4.2). Given you want a winter driver for your wife, I myself would lean towards the 4.2 if you can have it thoroughly checked out. Power is more linear without the turbo surge. Engine is rock solid, but little-no upgrades.

Having said that, I bought my 2.7T with 37k, chipped at 75k, replaced the clutch/flywheel at 85k, and it is now at 206k with stock turbos. I have been fighting CELs for the last year due to cats (replaced, but still throwing codes) and now the secondary air injection unit. Other than that dang CEL, she runs great and I will be keeping her indefinitely.

 

The other nice thing about the 2.7t is that the power is only there when you want it. Any turbocharged engine will give you lots more power than a NA engine (after all, that's the whole point) but if you don't put your foot in it, you get the economy of the smaller engine. Granted, with cars as heavy as our A6s, that may not be a lot of difference, but at today's gas prices, I'll take whatever I can get...
Jim

 

Clutches common to go out on the 2.7? I assume chipping will make it worse? What about the automatic in the 2.7, able to hold up under a chip?

 

Clutches wear in anything, the more power the faster. Tip also is famous for problems, again the more power, the more you stress the trans. More performance = more maintenance on any car...
Jim

 

Everything so far is spot on, rock solid advice. I have the 2.7T with tip trans, stock everything, 95K miles. Did the timing service myself about 10K miles ago. Little naggling problems are currently driving me nuts. Its a good daily driver, but I'm a bit scared to try to take it on trips. Currently devouring oil (valve cover gaskets, I hope) and leaking coolant (thermostat housing). and needs an O2 sensor to pass emissions (B2S2). All of these things are relatively minor and totally DIY able. Its just getting the money and time to get it taken care of. If I had to pay someone to do it, I would definitely be more broke...

with that, the 4.2 is recognized as being better, reliability wise. The 2.7T tends to have the bunch of little "issues" that crop up on a regular basis. Either one will be relatively reliable if you stay on top of the routine maintenance. Both have their "big ticket" repair nightmares that will cost more to fix than the car is worth, but these kinds of things happen any time you purchase a "previously enjoyed" vehicle, regardless of manufacturer.

good luck

 

I completely understand the more mods more problems comments. I have a 686 rwhp Z06 and I'm on my 3rd $1,500 clutch with less than 20,000 miles.

It seems that the 4.2 is the better option so I'll be looking for that.

thanks everyone!!

 

I vote for 02/03 S6. Yes it is a wagon. And yes, it is awesome.