Audi A3 Common Problems

The 7 Most Common Audi A3 Engine Problems

Chandler Stark

Meet Trey

Trey is an automotive enthusiast and has a huge passion for Volkswagen and Audi vehicles of all kinds. His enthusiasm started with the MK5 GTI, and he has massively expanded his knowledge over the years. When Trey is not delivering high-quality and in-depth content, we can usually find him working in his garage on his modified Genesis coupe. Trey created VW Tuning several years ago, and he is the primary visionary behind the content.

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Audi’s A3 was first introduced in 1996 and was marketed as a subcompact family car, and still is today. In its almost 3 decades of production, it has seen 4 different generations: 8L A3 (1996-2005), 8P A3 (2005-2013), 8V A3 ((2014-2021), and the newest version, 8Y A3 (2022-Present). The first two generations were built on the Volkswagen Group A platform, while the last two were built on the Volkswagen Group MQB platform.

Since this vehicle has been in production for so long and in many markets, you can expect there to be many engines. We’ll be going over the most common engines that are seen in the Audi A3’s, such as the 1.9TDI, 2.0TDI, 1.8t, 1.4TFSI, 1.8TFSI, and the 2.0TFSI. On top of those engines, there have been other engines in the S3 and RS3 sport versions of the Audi A3. Audi first released the S3 in 1999 and is still around today. In late 2010, Audi debuted the RS 3 and it is also still around today. Given that these are sportier versions of the A3, you can bet they’ve got some upgraded engines. In the S3, Audi featured a 1.8t 20vt and a 2.0TFSI, while the RS 3, the sportiest of the bunch, got a 2.5 TFSI that tops out at 400hp and 369lb-ft of torque in the latest version.

Common Audi A3 Engine Problems

Before jumping into the common problems of the Audi A3, since there are many engines and generations, we will try to differentiate the problems specific to the generations. With that said, the parts listed below will pertain to the generation referenced, so if you happen to have a different engine or generation and need assistance looking for parts, let us know in the comments! Some of the parts are listed for specific engine codes, PLEASE make sure your engine code fits the description.

  1. Ignition coil failure
  2. High-pressure fuel pump failure (HPFP)
  3. Faulty throttle body
  4. Fuel tank suction pump failure
  5. Diverter valve failure
  6. Faulty N80 valve
  7. Dual mass flywheel failure

1. Ignition Coil Failure

Unfortunately, premature ignition coil failure is common on many Audi engines. Ignition coils transform the voltage from the battery into the high voltage needed by the spark plugs to create a spark in the combustion chamber initiating engine combustion. Without one functioning ignition coil, you will more than likely experience engine misfires in that specific cylinder. However, if multiple coils have gone bad, the engine will be rough to start or not even start at all.

The main reason ignition coils go out is due to normal wear and tear because of the high engine temps they experience. Another main reason these go out is when an engine is modified. A modified engine should have upgraded ignition coils and colder spark plugs, so the engine can sustain the increased power. A good rule of thumb is spark plugs last around 30,000 miles and ignition coils tend to last around 60,000 miles.

Symptoms of Ignition Coil Pack Failure:

  • Check Engine Light (CEL) or Malfunction Indicator Light (MIL) illuminating
  • Engine misfires with P0300 – P0304 fault codes
  • Rough idle
  • Rough engine performance
  • Difficulty starting the engine

Ignition Coil Pack Replacement Options:

When it comes to replacing a failing or faulty ignition coil, we advise replacing all of the coils and spark plugs at once. Since we’re referencing the 2.0T engine, it has four cylinders, therefore will have four spark plugs, and four ignition coils. The main reason we like changing both sets of plugs and coils is to avoid any near future engine misfires with a new and old coil mixed. If you happen to know where both of these are located and know the correct spark plug gap, this is a rather simple DIY that shouldn’t take more than an hour. However, if you aren’t as comfortable, a mechanic will likely charge around $400 to replace spark plugs and ignition coils.

If you are tuned or plan on going tuned, we highly advise going with a set of 1-step colder spark plugs. The more boost you’re running, the hotter the engine gets, which leads to misfires under full throttle with OEM spark plugs.

Buy Here: A3 Coil Packs Replacement
Purchase Here: A3 Ignition Coil Packs + Spark Plug Set
Buy Here: 1-Step Colder A3 8V Spark Plugs
DIY Difficulty:

2. High-Pressure Fuel Pump Failure (HPFP)

Another very common problem with many Audi engines is a failing HPFP, not one specific A3 generation. An HPFP is used in direct injection engines and it pumps highly pressurized fuel directly into the engine. It is located on the driver side of the cylinder head and is driven by the engine’s cam. Without a proper functioning HPFP, there won’t be high pressurized fuel the engine needs which would cause rough engine performance.

There are a few reasons why the HPFP can fail: in 2.0T FSI engines, the cam follower had wear issues which would cause the HPFP to fail, while on other engines normal wear and tear was the reason it would fail. Whether it is because of a cam follower or normal wear and tear, the CEL will illuminate with P2293 or P0087 fault codes. The typical lifecycle of an HPFP is around 100,000 miles, depending on how well the engine is being taken care of.

Symptoms of HPFP Failure:

  • CEL or MIL illuminating
  • P0087 or P2293 fault codes present
  • Limp mode engaged
  • Low fuel pressure
  • Engine stutters
  • High engine temperature readings

HPFP Replacement Options:

When an HPFP fails, there are two options: you can replace it with an OEM unit or if you are modding your engine, it may be worth putting an aftermarket ultimate HPFP. When you do go replace the HPFP make sure to purchase a cam follower as well. There are many DIY videos online to assist in doing this yourself, but it isn’t the easiest DIY. A mechanic will likely charge around $500 to replace an HPFP.

Buy Here: A3 OEM HPFP Replacement
Buy Here: A3 Aftermarket Ultimate HPFP Kit
DIY Difficulty:

3. Faulty Throttle Body

Fortunately, a failing throttle body is not the most common problem, but it is more prevalent on 8P A3’s. A throttle body regulates the amount of air that flows in the engine and is crucial to a vehicle’s air intake system.

The main reason the throttle body fails is due to electrical connection issues with the throttle body. Audi has a harness repair kit to alleviate the electrical connection issues. Another reason the throttle body itself can fail is by becoming clogged with carbon buildup. If either is the case and the throttle body fails, you can get it professionally cleaned or replace it. Typically, a functioning throttle body should last throughout the lifecycle of the vehicle, besides the occasional cleaning of the housing.

Symptoms of Throttle Body Failure:

  • EPC light illuminating
  • P0122 fault code present
  • Rough idle
  • Vacuum leaks
  • Rough engine performance
  • Decreased fuel economy

Throttle Body Replacement Options:

When a throttle body starts to go, it is more than likely the sensors slowly going bad. These sensors control vital engine features in the engine’s ECU, so it is important to replace the throttle body as soon as possible. Unless you know your way around an engine, this DIY is not the easiest. A mechanic will likely charge around $700 to replace it.

Buy Here: A3 Throttle Body Replacement
DIY Difficulty:

4. Fuel Tank Suction Pump Failure

A defective fuel tank suction pump is seen most commonly in the 8V Audi A3. Audi issued a recall on affected 2016 A3s, so if you happen to have that year, check with your local dealership. A fuel tank suction pump is a pump that purges fuel from the EVAP system. When the fuel pump fails, fuel can flow directly into the EVAP system which could lead to major vehicle damage.

A typical fuel tank suction pump should last the whole lifecycle of a vehicle.

Symptoms of Fuel Tank Suction Pump Failure:

  • Fuel smell in the cabin
  • Power loss in mid-high RPMs
  • Clogged charcoal canister
  • CEL illuminating

Fuel Tank Suction Pump Replacement Options:

If you happen to have a defective fuel tank suction pump, it is crucial to get it replaced ASAP because it could cause a fuel leak which could cause catastrophic damage. If it does go out, the only option is to replace it. There aren’t too many DIYs online to assist in replacing the suction pump yourself, but if you know where it is located in the fuel tank it could save a couple hundred bucks in labor costs. A mechanic would likely charge around $1,000, unless it is covered under a recall.

DIY Difficulty: Intermediate

5. Diverter Valve Failure

Often referred to as “DV”, a diverter valve is not too common to fail, but it is common on the 1.8T and 2.0T engines. A DV is a boost pressure release valve that “diverts” unused boost back into the engine to avoid compressor surge. In Lehman terms, it is a valve that opens and closes to sustain boost pressure.

There are a few reasons the DV fails: the diaphragm rips, or the valve is stuck in the open or closed position. If the diaphragm happens to rip, engine performance will be severely dampened because boost pressure will be lost. If you happen to modify the A3’s engine for more power, the DV’s failure rate will increase due to the increased boost. It is not very likely for a DV to fail if the engine hasn’t been modified.

Symptoms of Diverter Valve Failure:

  • Noticeable boost loss or boost leaks
  • CEL or MIL illuminating with P0299 fault code
  • Rough idle
  • Poor engine performance
  • Poor fuel economy

Diverter Valve Replacement Options:

When a DV fails, whether the diaphragm rips or is stuck open, there are two options: replace it with an OEM DV or if you are modding the engine, it may be a good idea to purchase an aftermarket DV that can sustain more boost. Given that it is located on the side of the turbo, it isn’t a difficult DIY. However, if you aren’t comfortable enough doing a DIY, it shouldn’t cost you more than $250 depending on the cost of parts.

Buy Here: A3 Diverter Valve Replacement
DIY Difficulty:

6. Faulty N80 Valve

An N80 valve, or the EVAP purge valve, is very common to fail in many Audi and Volkswagen engines, including the A3. The N80 valve is a component in the EVAP system that regulates the fuel vapors that are recycled into the intake manifold to get burned off. Without a functioning EVAP purge valve, too much or too little fuel vapor can be held in the engine causing a CEL.

The main reasons these valves fail are: normal wear and tear or is defective out of the factory. It can be quite alarming when they fail because customers have reported a loud popping noise coming from the trunk after fueling up their vehicle. A good thing is that it is a very distinguishable noise, so you will be able to know what is wrong when it occurs. This is caused by the valve being stuck open causing the fuel tank to pressurize and pop. Typically an N80 valve should last the lifecycle of a vehicle, but with an Audi or Volkswagen, you can expect to go through at least one of these valves.

Symptoms of N80 Valve Failure:

  • CEL or MIL illuminating with P0441, P0442, P0171, or P0172 fault codes
  • Popping noise from the trunk post fueling up
  • Rough engine performance
  • Reduced fuel efficiency

N80 Valve Replacement Options:

When an N80 valve goes out or is stuck, the only thing to do is to replace it. It’s a cheap part and a rather simple DIY if you know the location of the valve. If you happen to have any of the fault codes above, you will want to check this first because the engine will run rough until it is fixed. A mechanic would likely charge anywhere from $150 – $250 mainly depending on labor costs.

Buy Here: A3 N80 Valve Replacement
DIY Difficulty:

7. Dual Mass Flywheel (DMF) Failure

This problem has been most reported on 8P A3 generations, but it can occur on any other generation as well. A Dual Mass Flywheel is found at the bottom of the crankshaft and serves two main purposes: reduces engine vibrations, gives the vehicle better overall driveability.

When the DMF fails, it will rattle under the floorboard because of a spring falling out of the actual unit. When an engine is modified for more power, the likelihood of a DMF failing increases due to the added torque. On a normal vehicle, the DMF shouldn’t fail, but on a modified vehicle, you will more than likely go through one DMF.

Symptoms of DMF Failure:

  • Rattling noise while the engine is cold
  • Excessive vibration while turning the vehicle off
  • Hard clutch
  • Clutch slippage
  • Rough shifting

DMF Replacement Options:

Whenever any of the above symptoms are experienced, it is important to act on the DMF ASAP. If ignored, it could cause major engine damage. When a DMF does happen to go out, the only thing to do is to replace it. If you plan on modifying your A3 for more power, it may not be a bad idea to get an aftermarket DMF to avoid clutch slippage with more power. This is certainly not an easy DIY unless you know where the DMF is located and have the proper tools. A mechanic would likely charge around $800 to replace it, if not more.

DIY Difficulty: Difficult

Audi A3 Reliability

The Audi A3 received a reliability rating of 51.75/100 which puts it at below average of 57. The average annual cost of maintenance is $741, which is above the $651 average. From our research, it seems that the 8P (2005-2013) generation has the most problems. So if you are in the market for a used A3, try to avoid that generation if possible. However, just like any other vehicle, if it is taken care of well, then it will easily last over 200,000 miles.

If you want to read up on more Audi content, here’s our write-up on “The 5 Best Audi A3 Mods.

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