The Audi A6 C7 has now dropped in price to the point where it caught the attention of many used car buyers. One of the most common and arguably the best engine to go with this car is the 3.0 TDI. If you’re in a market for a C7 Audi A6 with the 3.0 TDI engine, we recommend you stay with us!
Doing your own research before you purchase a high-tech car like an Audi is always a good idea. Trust us, you don’t want to buy a poorly maintained diesel. Especially when it comes to Audi models. These cars are very expensive, both to purchase and to maintain, and one wrong decision can quickly drain your wallet. But you shouldn’t worry because that’s why we are here to help you out.
First, we are going to learn the basic Audi A6 C7 3.0 TDI engine specs and see what this engine is packing. Then, we are going to share with you the most common Audi A6 C7 3.0 TDI problems and learn more about the issues that this model has. So, without further ado, let’s dive into the article and learn more about the issues of this engine.
Basic Audi A6 C7 3.0 TDI Specs
Now before we cover the problems of this 3.0 TDI engine, let’s first focus on the specs. Since specs are also important when it comes to purchasing your future vehicle.
As you probably know, the 3.0 TDI is one engine that has been in production for a really long time. But what is worth noting is that this was not always the same engine.
In 2013, the second generation of the 3.0 TDI was introduced. This engine replaced the engine that was in production from 2003.
This new engine, although an evolution, has brought a lot of new things. Mainly, weight savings and increase in horsepower and torque output.
This new engine saves 55 pounds in weight compared to its predecessor, which is quite a lot. And one major upgrade is the switch from four chain timing setup to two chain setup. Which increased the reliability of the engine.
In addition to this, there were also other power upgrades that allow this engine to make 15 hp and 22 lb-ft of torque more compared to the original engine.
This engine also includes a Garrett variable geometry turbo, a new intercooler, Piezo injectors, a high-pressure Bosch CP4.2 fuel pump, and a ton of other improvements.
Nevertheless, here are the full specs of the second-generation 3.0 TDI engine.
- Configuration: V6
- Displacement 3.0L
- Cylinder Bore: 83 mm
- Piston Stroke: 91.4 mm
- Block Material: Compacted Graphite Iron
- Head Material: Aluminum
- Head Design: DOHC, 4 valves per cylinder
- Compression Ratio: 16.8:1
- Turbocharger: Garrett VGT Turbocharger
- Fuel Injection: Common Rail
- Horsepower: 215 – 268 hp
- Torque: 369 – 428 lb-ft (500 – 580 N-m)
Common Audi A6 C7 3.0 TDI Problems
Common problems with the second generation 3.0 TDI engine from the Audi A6 C7 include:
- Injector & Injector Bolts Failure
- HPFP Failure
- Turbocharger Failure
- Crank Pulley Failures
- Oil & Coolant Leaks
- Timing Chain Tensioner Failures
- EGR Valve Clogs Up
- Swirl Flap Failures
- DPF Clogged Up
Now that we covered briefly the Audi A6 C7 3.0 TDI problems, we can move on and learn more about them in-depth.
In other words, when and how they occur. This is really important for you to get an idea of when and how you can expect these problems. So, let’s get started.
Injector & Injector Bolts Failure
This engine has some problems with the injector bolts. The injector bolts are the bolts that are holding the injectors in their place.
What can happen with these injector bolts is that they can get loose or break. Resulting in loose injectors that can move around. There will be other symptoms like rattling noises, check engine light, limp mode, and cylinder misfire.
Also, the injectors can fail on these engines. This failure usually occurs somewhere at 200,000 km. These injectors either leak or end up clogged up.
The solution is to replace them or rebuild them if you can find a shop that does that.
This engine is equipped with a high-pressure fuel pump, also known as HPFP. This fuel pump is a Bosh unit that can break sometimes.
This fuel pump is mounted in the rear end of the valley of the engine and is chain driven. What can happen with this fuel pump is that it can fail.
These failures often occur at 400,000 km. So, if you have a high mileage engine, it is a good idea to replace this pump just for a good measure because when it fails, it can damage the injectors in the process.
This is why doing this as preventive maintenance when you do the timing chain is a good idea.
This engine uses a variable geometry turbocharger that is also mounted in the valley of the engine and this VGT turbo can fail.
These turbos are much more sensitive to poor maintenance. So, if you skip your oil changes, you can damage the turbo prematurely.
Although these turbos should easily last for 200,000 km. Usually at this mileage, they start creating symptoms like whistling noises and also loss of power when they fail.
The solution is to rebuild the turbo or replace it with a new one. Now let’s move on to the next Audi A6 C7 3.0 TDI problems.
Crank Pulley Failures
Another failure point on this engine is the crank pulley. So, what is a crank pulley and why does it fail?
This pulley is mounted on the crankshaft itself and this pulley has the role of powering the accessories. This is done through the serpentine belt.
What can happen is that these pulleys are made out of rubber and this rubber can tear. So, you will end up losing the accessories in the process.
If you note that the pulley wobbles it is a good idea to replace it.
Coolant & Oil Leaks
Oil leaks are common on these engines, they can leak oil from a lot of different places around the engine.
More specifically, the gasket of the oil cooler and the oil cooler base plate can leak, and the O-rings of the plastic coolant flange located in the valley can also leak coolant.
There is also a plastic coolant regulating valve that can leak coolant. The plastic coolant cover that is mounted on the engine cover can also leak coolant.
Another common place for oil leaks is the oil filter housing. There are few gaskets that can leak oil. As well as the oil filter housing itself can crack and leak oil.
The oil thermostat O-ring can also leak oil. And another common place for developing leaks is the plastic hose that drives coolant on top of the engine.
And last but not least are the rear timing cover and the rear main seal which can also develop oil leaks.
Overall, this engine can leak from a lot of places.
Timing Chain Tensioner Failures
The timing chain can also cause problems for a lot of owners. The 3.0 TDI is chain driven, and this chain is mounted at the rear of the engine.
The chain itself should last for 200,000 km, but sometimes it can start to rattle because of a bad timing chain tensioner.
This timing chain tensioner can cause a lot of headaches. Also, the timing chain itself can start to rattle when it wears out.
So, replacing this chain, the tensioner, and other things can cost you a good penny. Mainly because the engine has to be removed from the car.
So, you get the idea why this is a problem that you have to avoid. It is very expensive to fix. Watch out for cars that rattle, the timing chain is probably gone.
EGR Valve Clogs Up
The EGR valve also tends to clog up on this engine. So, what is this EGR valve? The EGR valve for those who don’t know is an emission’s device.
This device recirculates some exhaust gasses into the intake manifold, thus, reducing pollution.
These valves are full of carbon after certain mileage and they require cleaning or replacement. Common symptoms associated with this valve are the check engine light and loss of power.
Swirl Flap Failures
The swirl flaps on the intake manifold are another common failure point in these diesel engines.
Diesel engines are using swirl flaps and these flaps are clogged with carbon deposits and start to malfunction. Some owners delete them completely whenever they start causing issues.
DPF Clogged Up
And last but not least is the DPF, the diesel particulate filter can clog up and cause many headaches to owners.
This is the case because owners are not regenerating this filter. Eventually, the filter will clog up and manual cleaning will be needed. Make sure you read our guide on how to maintain and drive a diesel engine to avoid engine problems.
Which Models Have The Audi 3.0 TDI Engine?
Besides the A6 C7 this engine can be found in the following models.
- Audi A4
- Audi A5
- Audi A6
- Audi A7
- Audi A8
- Audi Q7
- Audi Q8
- WV Touareg
- Porsche Cayenne
Common Audi A6 C7 3.0 TDI Problems?
Common problems with this engine include oil leaks, coolant leaks, timing chain rattle, injector failure, HPFP failure, turbocharger failures, crank pulley failure, DPF and EGR failures. These are the most common issues.
Is The A6 C7 3.0 TDI Reliable?
This engine is fairly reliable if you purchase the car new or with low miles. If the car has a lot of miles, then you better stay away because these issues that are often wear and tear items can drain your wallet rather quickly.