Looking for an Audi A6 C6 2.7 TDI review? Chances are you've found a big Audi with a V6 diesel engine for the price of a decent four-cylinder car. Sounds like a bargain, doesn't it? Six cylinders, a smooth, quiet engine, motorway comfort and the feeling of driving a proper car. And sometimes it really is a good buy. But there's one thing people often forget: the Audi A6 C6 might have become cheap to buy, but repairing a V6 certainly hasn't. Let me explain when I'd buy one and when I'd walk away.
Who is the Audi A6 C6 2.7 TDI for?
If you spend a lot of time on the motorway, enjoy relaxed journeys and love the smooth, quiet sound of a six-cylinder diesel, the A6 C6 2.7 TDI has plenty to offer. It's a car for someone who appreciates comfort and understands that a good car needs looking after. You don't need to be a mechanic, but you do need to be prepared to take care of your engine. If you're looking for a cheap car that you can just fill up and drive, I'd suggest looking elsewhere. Because with this Audi, putting off maintenance can turn into a very expensive repair surprisingly quickly.
Which engines and gearboxes are available?
The Audi A6 C6, also known as the 4F, was produced from 2004 to 2011. Under the bonnet of the 2.7 TDI is a V6 diesel that runs smoothly and feels particularly comfortable on long journeys. But before buying one, you need to know exactly which version you're looking at and which gearbox it has. That makes a big difference to what you'll need to maintain later.
- 2.7 TDI V6, engine code BPP – 180 hp. After the facelift, power increased to 190 hp.
- 6-speed manual gearbox – the option for drivers who prefer changing gears themselves.
- Multitronic with front-wheel drive – an automatic gearbox that needs careful attention and regular servicing.
- 6-speed Tiptronic with quattro – the automatic gearbox fitted to the four-wheel-drive version.
What problems do we see on the Audi A6 C6 2.7 TDI?
Swirl flaps
This is one of the best-known weak points of the BPP engine. Inside the intake manifolds are plastic flaps that control how air flows into the engine. When they start causing trouble, the check engine warning light comes on and the car may lose power. An owner comes in and says, "The engine light's on and it doesn't pull like it used to." The worrying part is that pieces of these flaps can sometimes put the engine itself at risk. That's why I wouldn't simply clear the fault code and pretend everything was fine.
Timing chains at the back of the engine
If the engine rattles when you start it from cold, you need to pay serious attention to the timing chains, tensioners and guides. On this V6, the timing chains are at the back of the engine, next to the gearbox. That means replacing them isn't a routine service job. It's a major repair. I've explained why so much work is involved in my article 3.0 TDI: Why the Engine Has to Come Out to Replace the Timing Chains. The 2.7 TDI belongs to the same engine family, and the problem with the chain location is very similar. That's why a cold start before buying is absolutely essential.
Oil leaks, EGR and injectors
On this engine, I always look carefully for oil leaks around the oil cooler and its seals. As the mileage increases, carbon deposits also build up in the EGR system, which sends some of the exhaust gases back into the engine. The piezo injectors deserve attention too, especially on a high-mileage car. I'm not saying every A6 suffers from all these problems. I'm saying you need to check for them before handing over your money. Because knowing what you're buying is one thing. Discovering the problems after you've bought it is quite another.
Multitronic
If you're looking at a front-wheel-drive A6 with Multitronic, pay particular attention to the gearbox. I often hear owners say, "The gearbox jerks," and sometimes they tell me the PRNDS display is flashing on the dashboard. That's not something you should simply accept as normal. Multitronic has its own particular issues and needs proper diagnostics. If you'd like to understand more, read Multitronic: Why It Jerks and Can It Be Repaired?.
What should I check before buying?
This is where I'd be especially careful. A lovely interior and shiny paintwork tell you nothing about what's happening inside the engine or gearbox. Don't just take the seller's word for it when they say, "Everything's been serviced." Ask for the service history and get the car properly inspected.
- Start the engine when it's completely cold. Listen for rattling and use diagnostics to check the camshaft timing synchronisation.
- Check the swirl flaps and any stored fault codes. Just because the check engine light isn't on doesn't mean everything is fine.
- Inspect the engine from above and below for leaks around the oil cooler and seals.
- Test-drive the automatic gearbox, whether it's Multitronic or Tiptronic. Find out when the gearbox oil was last changed and ask for proof.
These are exactly the things we check during our pre-purchase inspectionat Das Auto Service. I'd much rather tell you about a problem before you buy the car than discover it together afterwards. By then, your options are a lot more limited.
How should I service the Audi A6 C6 2.7 TDI?
With an older V6 diesel, proper maintenance matters far more than promises of huge service intervals. Manufacturers also have emissions targets to meet, but my priority is keeping your engine healthy. Especially when the car has already covered a lot of miles. Here's what I recommend for cars driven in Bulgaria.
- Engine oil and all filters – oil, fuel, air and cabin – every 10,000 km or once a year, whichever comes first. This applies regardless of the oil used or the LongLife service interval.
- Tiptronic – change the gearbox oil every 120,000 km, together with the front differential and transfer case oils. Gearbox adaptation is essential after servicing.
- Multitronic – change the gearbox oil every 60,000 km using genuine oil, followed by mandatory gearbox adaptation.
- Crankcase ventilation filter – replace every 80,000 km.
- Brake fluid – replace every 2 years. Coolant – replace every third heating season.
- Air conditioning – service every spring, including a system check and replacement of the receiver-drier and the oil in the system. Simply topping up the refrigerant isn't a proper service.
- Full workshop inspection – every 6 months.
If you'd like to keep your maintenance organised, have a look at my Audi A6 C6 2.7 and 3.0 TDI Service Schedule. That way, you won't have to wait for something to break before giving it the attention it needs.
IMPORTANT! Mistakes with a V6 TDI can be expensive, and you're the one who ends up paying the bill. Buying the car is only the first expense. Don't buy one just because the asking price looks tempting.
What's my verdict on the Audi A6 C6 2.7 TDI?
I'd buy an Audi A6 C6 2.7 TDI if the timing chains and swirl flaps had been checked, the gearbox was working properly and the car had a clear service history. In that case, you're getting a comfortable V6 diesel that makes a lot of sense for long journeys. But if the advert promises a "cheap A6 with a V6" and nobody can show you what's actually been serviced, I'd walk away. Not because it's a bad model, but because neglected maintenance can cost far more than you expect. I want you to buy a lovely car, not somebody else's unfinished repair bills.
Tip from Kris Mladenov: When buying a 2.7 TDI, set some money aside for the timing chains, even if the engine sounds perfectly healthy. If it turns out they don't need replacing, brilliant. But if they do, at least one of the biggest repair jobs on this engine won't catch you by surprise.
I hope you've found this article useful! If you have, I'd really appreciate you sharing it with a friend who's thinking about buying an Audi A6 C6 2.7 TDI. My mission is simple: when I know something useful, I want more people to know it too. That means more properly maintained cars on the road and fewer owners paying for mistakes that could have been avoided.
The solution in our shop
Genuine Longlife III FE 0W30 oil 5L
LongLife III engine oil is used for engine servicing. Regardless of the oil type, I recommend changing the engine oil and all filters every 10,000 km or once a year, whichever comes first.
View in shop
Genuine Audi Multitronic automatic gearbox service set
The Multitronic service kit is designed for proper maintenance of this gearbox. Adaptation is essential after changing the oil.
View in shop
Genuine automatic gearbox oil G052516A2 1l
Genuine automatic gearbox oil. Using the correct oil is important for proper gearbox operation and a long service life.
View in shopRead more
- Pre-purchase inspection
- Engine overhauls
- Audi A6 C6 2.7 and 3.0 TDI Service Schedule
- 3.0 TDI Timing Chain Replacement: Why Remove the Engine?
- Audi Multitronic Gearbox Problems: Causes and Repairs
Frequently asked questions
What are the most common Audi A6 C6 2.7 TDI problems?
The main things to watch are the swirl flaps, timing chains and tensioners, oil cooler leaks, EGR system and piezo injectors. On Multitronic models, also watch for jerking and a flashing PRNDS display.
Should I choose the 2.7 TDI or 3.0 TDI in an Audi A6 C6?
With these V6 engines, I'd focus mainly on the condition and service history of the individual car. A properly inspected 2.7 TDI is a more sensible purchase than an unchecked 3.0 TDI bought simply because of the seller's promises.
How long do the timing chains last on the Audi A6 C6 2.7 TDI?
There's no fixed mileage at which they're guaranteed to fail. What matters is how the engine sounds on a cold start, the condition of the tensioners and guides, and the results of a diagnostic check of the camshaft timing synchronisation.
How often should Multitronic gearbox oil be changed?
I recommend changing it every 60,000 km using genuine oil. Gearbox adaptation is essential after servicing.