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The Audi A6 C7 was first introduced in 2011 and is the A6’s fourth generation since its inception. It was built on the Volkswagen Group’s MLB platform. This A6 is commonly referred to as the C7 A6 or C7.5 A6, depending on what model years are being talked about. It went through a facelift in 2015, which is commonly referred to as the C7.5 A6. Only two body styles are available for this A6: a four-door sedan and a five-door station wagon (avant).
There are two engines that are the most common for this Audi and it is a 2.0T TFSI and a supercharged 3.0T TFSI. There were two versions of the 2.0 TFSI, a less powerful and a more powerful. The less powerful 2.0T TFSI put out 178hp (132 kW) and 236lb-ft of torque, while the more powerful 2.0T TFSI put out 208hp (155 kW) and 258lb-ft of torque. There were also two different 3.0T engines. The first engine was produced from 2011-2012 and put out 296hp (221 kW) and 325lb-ft of torque. The second engine was produced from 2012-2018 and put out 306hp (228 kW) and 324 lb-ft of torque.
Audi A6 C7 Engines
The 2.0T and 3.0T are just two out of the many engines that the fourth-generation A6 had to offer. See below for a full list of engines with specs:
Audi A6 C7 Engines & Engine Specs
Audi A6 C7 Specs
In this section, we will be going over the interior and exterior specs for both the four-door sedan and five-door station wagon.
Audi C6 A7 Dimensions
Next up, probably the most anticipated information, the most common problems seen in A6 C7’s.
The 7 Most Common Audi A6 C7 Engine Problems
- Ignition coil or coil pack failure
- Leaking timing covers
- Timing chain tensioner failure
- Carbon buildup
- Motor mount failure
- Premature water pump and thermostat failure
- Premature wheel bearing failure
Before jumping into the common problems of the Audi A6 C7, since there are many engines, we will try to differentiate the problems specific to the engines. PLEASE make sure the replacement parts listed below fit your specific engine. If you need assistance with engines other than the 3.0T or 2.0T, let us know in the comments below.
1. Ignition Coil or Coil Pack Failure
Premature ignition coils or coil packs is the most common failure across most modern engines nowadays. The C7 is no exception, and it is more common on the 2.0T engines. An ignition coil transforms the lower voltage in the battery into higher voltage that the spark plugs need. Once the higher voltage reaches the spark plugs, the combustion process begins. Needless today, coils are crucial ignition components in an engine. There are as many ignition coils as there are cylinders in an engine. Without one functioning ignition coil, a vehicle is still able to function, but an engine misfire will be experienced in the specific cylinder.
There are a few reasons ignition coils can go bad: normal wear and tear, defective out of the factory, and engine modifications pushing 40+ more hp out of the engine. The maintenance interval for spark plugs is to change them every 35,000 miles. We would advise replacing both the spark plugs and ignition coils/coil packs at the same interval. This ensures freshness from the ignition products.
Symptoms of Ignition Coil or Coil Pack Failure:
- Malfunction Indicator Light (MIL) or Check Engine Light (CEL) illuminating
- Engine misfires with P0300 – P0306 fault codes present
- Rough idle
- Rough engine performance
- Difficulty turning over the engine
Ignition Coil Replacement Options:
Once an ignition coil goes bad, the only thing to do is to replace it. When one ignition coil goes bad, we would advise ordering a brand new set and replacing all of them. The reason being is because they tend to go out around the same time and it avoids any near future cylinder misfires. To replace ignition coils and spark plugs is not a terribly difficult DIY with the proper tools. However, if you aren’t keen on doing this service on your own, a mechanic will likely charge around $300-$450 to replace all ignition coils.
2. Leaking Timing Covers
This is a problem that is more common on the 3.0T supercharged engine, specifically early A6 C7 model years. A timing cover, often referred to as a timing chain cover, is a plastic cover that protects the timing components from any external debris. On the 3.0T engine, it is predominantly the rear upper timing covers that are the issue. If an Audi A6 C7 is illuminating a low oil pressure indicator more often than it should, this would be the first place we would advise looking.
When a plastic component in an engine is exposed to extreme heat, there is a low likelihood that this component will last the full life cycle of a vehicle. This is what happens with the timing chain cover and unfortunately, it is very hard to prevent. We have seen many C7 owners having to replace multiple timing covers throughout the life cycle of their vehicle.
Symptoms of Leaking Timing Covers:
- Leaking oil from the timing portion of an engine
- Low oil indicator illuminating more often than normal
- Having to put more oil in an engine
- High engine oil consumption
- Rough engine performance
- White smoke emitting from the engine
Timing Cover Replacement Options:
This is not the easiest DIY, but would save anyone a lot of money due to labor costs. The replacement covers themselves are relatively inexpensive, but it requires many labor hours to replace them. A dealership will likely charge anywhere from $700 – $850 to replace a single timing cover.
3. Timing Chain Tensioner Failure
Timing chain tensioner failure was predominantly found in the 2.0T engines and is the main reason the engine gets a bad rep. VW has since fixed the issue, but can still be found in Gen 2 2.0T TSI engines. A timing chain connects the camshaft to the crankshaft, which opens and closes the intake and exhaust valves. The timing chain tensioner maintains optimal tension of the timing chain. Depending on the engine, there can be two tensioners (2.0T) or four tensioners (3.0T). As a general rule of thumb, there is one tensioner per one timing chain.
A timing chain tensioner should last throughout the lifecycle of a vehicle, but are not very reliable in VW or Audi engines. There can be very costly damage to an engine if this issue is ignored. If a tensioner fails, the timing chain can jump and sometimes snap, which would cause the valves to collide with the pistons. This would be a worst-case scenario. Unfortunately, there isn’t a maintenance interval to go off for the timing chain because Volkswagen claims the timing chain is a lifetime component.
Symptoms of Timing Chain Tensioner Failure:
- VW death rattle (“Marbles in a can”)
- Engine dying
- Rough engine performance
- Engine timing off
- Stretched timing chain
Timing Chain Tensioner Replacement Options:
If you suspect a timing chain tensioner going bad, although expensive, we would advise replacing the associated tensioners, guides, and timing chain. Because it would be pointless to spend money on labor to replace just a couple or a few tensioners. If you happen to have the proper tools and expertise to perform this service, we would highly recommend doing so as it is a very expensive service.
4. Carbon Buildup
This is a common problem in most direct injection engines nowadays, not just VW and Audi engines. Specifically, the 2.0T engines experience carbon buildup more often in the A6 C7s. Direct injection is when petrol is pumped directly into the cylinders via injectors. Over time, the intake valves and ports will become clogged with carbon or soot. There are ways to prevent buildup, but there isn’t really anything that can be done to completely avoid carbon buildup. We would advise at least checking the ports and vales every 30,000 miles.
Carbon buildup can severely impact engine performance. To relate, imagine breathing with clear sinuses versus clogged sinuses. With clear sinuses, oxygen intake is higher than when clogged. Essentially an engine with carbon buildup vs an engine without carbon buildup is night and day when it comes to engine performance. It is more likely to occur on vehicles that only take short commutes every day vs longer commutes. This is because longer commutes tend to have higher engine temps and burn off soot or carbon while running.
Symptoms of Carbon Buildup:
- Decreased engine performance
- Cold start misfires
- Poor fuel economy
- Engine knocking
Ways to Prevent Carbon Buildup:
- Replace ignition components regularly
- Use the highest quality fuel on refills
- Perform or get oil changes regularly
- Manually clean the valves or ports every 30,000 miles
- Run the engine hard ever so often
- Get intake valves walnut blasted or professionally cleaned every 60,000 miles
5. Motor Mount Failure
Motor mount failure is common on Audi engines, specifically the 3.0T and 4.0T engines. This is not to say it isn’t possible for motor mounts to fail on the 2.0Ts, but far less common. Motor mounts hold the engine in place and dampen engine vibrations while the vehicle is idle or in motion. Without functioning motor mounts, you will definitely notice the driving experience deteriorate dramatically as engine vibrations won’t be subtle and will be noticeable.
The main reasons motor mounts fail are hydraulic fluid leaks. Without sufficient hydraulic fluid, a motor mount can not properly dampen vibrations or keep the motor in place. Motor mounts should be lifetime parts, but unfortunately aren’t on some high-end Audi engines.
Symptoms of Motor Mount Failure:
- Noticeable engine vibrations
- Clunking noises from the engine bay
- Engine movement while driving
- Low hydraulic fluid
- Rocky startup on startup
- Engine misalignment in the engine bay
Motor Mount Replacement Options:
It is important to act immediately when you notice heavy engine vibrations because it is not great for an engine to be knocking around in the engine bay. When one happens to fail, we would advise just replacing them both. Now when it comes to OEM vs aftermarket, we would always go the aftermarket route because clearly, the OEM mounts are less reliable. Depending on labor rates, a motor mount replacement could run up to $1,000.
6. Premature Water Pump and Thermostat Failure
Water pumps and thermostats, aside from ignition coils and spark plugs, are one of the most common failures amongst most vehicles on the road. A water pump maintains coolant flow from the radiator to the engine block. While the thermostat regulates how much coolant is cooled by the radiator before being recycled and the amount of coolant that is recycled back into the engine. Early generation 3.0T’s had thermostats that would be stuck in the open or closed position and water pumps leaking coolant. But this is also common in 2.0T engines. Both cooling components will fail at least once in a vehicle’s lifecycle.
Symptoms of Water Pump and Thermostat Failure:
- Low engine coolant/antifreeze indicator illuminating (more often than normal)
- Engine overheating
- Limp mode engaged
- Coolant leaking under the car
- Sweet smell in the engine bay
- Erratic temperature readings
Water Pump and Thermostat Replacement Options:
When either cooling component goes out, we would advise replacing both the thermostat and water pump. Now if you want to be really safe, you should get a water pump kit, which replaces everything associated with the water pump. This can include the water pump, thermostat, timing belt, pulleys, and coolant. This isn’t the worst DIY, but on some engines, it could be quite difficult. A mechanic or dealer will likely charge around $1,000 to replace both the water pump and thermostat.
7. Premature Wheel Bearing Failure
We understand this isn’t specifically an engine problem, but we have heard many instances of A6 C7 owners having to replace wheel bearings multiple times throughout the vehicle’s life cycle. Wheel bearings allow the wheel, wheel hub, and tire to work together. In Lehman terms, it allows a frictionless rotation of the hub assembly, which supplies smooth tire rotation. There are a couple of reasons these can fail: bad roads and road impact. In other words, if you don’t avoid potholes or slow down on speed bumps, your vehicle is on a fast track to wheel bearing failure. When wheel bearings go bad, like motor mounts, you’ll be able to tell immediately that something is up with your ride.
Symptoms of Wheel Bearing Failure:
- Loose or veering steering
- Uneven tire wear
- Steering wheel vibration while turning
- Humming or rumbling noise while turning or accelerating
Wheel Bearing Replacement Options:
When they do go out, there aren’t very many choices to choose between: replace them with OEM or aftermarket. That’s about it. This is not an easy DIY and we wouldn’t advise doing so unless you have some sort of automotive expertise. A rear wheel bearing replacement can cost around $700 at a dealership, but this is typically cheaper at a local shop.
Audi A6 C7 Mods
The 5 Best Mods for a 3.0T Audi A6 C7
Now that we’ve covered the common problems, let’s jump into the fun part. For the mods listed below, we will be focusing on the 3.0T engine. With all of the supporting mods and proper tunes, an A6 C7 could push a whopping 550hp. For fun, we’ve seen C7 owners pushing 10-second quarter miles, which is extremely impressive for a luxury sedan.
- ECU Tune
- Ultracharger/Throttle Body Upgrade Kit
- Heat Exchanger
- TCU Tune
If you are wanting to read more about the mods listed above, we have a full article on “The 5 Best Audi A6 C7 Mods“.
Audi A6 C7 Reliability
Is the Audi A6 C7 reliable? This A6 doesn’t get the best reputation when it comes to reliability reviews. From 2012-2013, there were engine problems detected, from 2014-2016, there were fuel system issues detected, 2014 and 2016 model years had brake issues, and lastly, there were power equipment issues for 2013 and 2019 model years. In our opinion, the 3.0 TDI engine would be the most reliable, and the most reliable model years would be 2017-2018. With all of this said, these are reliable mechanical cars if proper maintenance is kept up with, especially over 100,000 miles. Now, we have seen many A6 C7s last up to 150,000 miles.