2013-2017 Audi A4, A5, Q5 & Allroad Alternator: Decoding Whining Noises and Charging Issues

Symptoms of a Failing Alternator

When the alternator in your Audi begins to fail, it can cause a variety of electrical and mechanical symptoms. Recognizing these signs early can help you avoid a breakdown.

Electrical Symptoms

• Battery Warning Light: The most obvious sign is a battery-shaped warning light on your dashboard. This light indicates a problem within the charging system, and while it could be a battery issue, it's often the first sign of a failing alternator.
• Dimming or Flickering Lights: You may notice your headlights and dashboard lights dim or flicker, especially at idle or when using multiple accessories like the heater and radio. Conversely, lights might also become unusually bright if the voltage regulator inside the alternator fails.
• Slow or Malfunctioning Accessories: Power windows that operate slower than usual, an erratic radio, or other misbehaving electronics can point to the alternator not providing enough consistent power.
• Difficulty Starting or Frequent Stalling: A weak alternator won't properly charge the battery. This can lead to a dead battery, a slow-cranking engine, or an engine that stalls frequently because there isn't enough power for the spark plugs and fuel system.

Noises and Smells

• Whining or Grinding Noises: A high-pitched whining or a grinding sound coming from the front of the engine is a classic sign of bad alternator bearings. This noise will typically change pitch and volume with engine speed.
• Squealing Noise: A loud squeal often points to a problem with the serpentine belt that drives the alternator. The belt could be slipping on the alternator's pulley due to wear or a failing tensioner.
• Burning Smell: A smell like burning rubber or an electrical fire can indicate that the alternator is overheating or its drive belt is slipping and creating excessive friction. An overloaded alternator can push too much current through its wires, causing them to heat up and produce a dangerous odor.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

While there are no specific recalls for the alternator itself on these models, several related recalls and issues are important for owners to be aware of.

• NHTSA Recall 18V229 (Coolant Pump): Affects 2013-2017 A5 and Q5, and 2013-2016 A4 and Allroad models. The electric coolant pump can become blocked with debris, leading to overheating and a potential fire risk. While not directly the alternator, any major electrical issue or engine fire can damage related components.
• NHTSA Recall 17V622 (Auxiliary Heater): Affects 2013-2016 A4, A5, Allroad, and Q5 models. Corrosion in the auxiliary heater's electrical connector can cause wires to overheat and melt, increasing the risk of a fire. This highlights the sensitivity of the vehicle's electrical system.
• NHTSA Recall 14V667 (Airbags): Affects 2013-2015 A4 and Allroad models. An improper algorithm in the airbag control module could prevent frontal airbags from deploying in a secondary impact.
• NHTSA Recall on Fuel Pump Flange (Q5): Affects 2013-2017 Q5 models. The fuel pump flange may develop cracks, which could lead to a fuel leak and fire risk.

No Technical Service Bulletins (TSBs) directly related to widespread alternator failure on these specific models were found during research. Most issues appear to be related to normal wear and tear.

Buying a Used Alternator: What to Look For

A quality used OEM alternator can be a reliable and cost-effective alternative to an expensive new unit. Here’s how to choose a good one.

1. Verify Part Numbers: Check for OEM part numbers like 06H903017K, 06H903018M, or Valeo number 439798. This is the best way to ensure a perfect match.
2. Physical Inspection:
   • Housing: Look for any cracks or significant corrosion on the aluminum housing.
   • Pulley: The pulley should be clean, free of damage, and spin smoothly by hand. A rough or noisy pulley indicates bad bearings. This alternator uses a 6-groove clutch pulley.
   • Electrical Connectors: Ensure the plastic connectors are not cracked or broken and the metal terminals are clean and free of corrosion.
3. Mileage Considerations: Alternator failure is often related to mileage and usage. While there's no exact lifespan, failures become more common after 100,000 miles. A used unit from a lower-mileage vehicle is generally a safer bet.
4. Why Used OEM vs. New Aftermarket: An original equipment (OEM) Valeo alternator is designed specifically for your Audi's electrical system. It ensures proper voltage regulation and fitment. Cheaper aftermarket alternators can sometimes cause issues with sensitive vehicle electronics or have a shorter lifespan, making a reliable, low-mileage used OEM part a smarter choice.

Cost of Replacement

The cost to replace an alternator can vary significantly based on the part source and labor rates. Getting a professional repair can be expensive, with the majority of the cost often being the part itself.

Replacement Overview & Related Parts

Replacing the alternator on the 2.0T engine in these Audis is a moderately difficult job that can be done by an experienced DIYer. Access is tight at the front of the engine.

Key Steps:

1. Release Belt Tension: Use a long wrench (typically 17mm or 18mm) on the serpentine belt tensioner to relieve tension and slip the belt off the alternator pulley.
2. Remove Mounting Bolts: The alternator is typically held on by two to four bolts (often 6mm Allen head bolts). Accessing the lower bolt can be tricky.
3. Disconnect Wiring: Remove the main power cable (held by a nut) and the electrical connector from the back of the alternator.
4. Installation: Installation is the reverse of removal. Torque the alternator mounting bolts to the correct specification, which is approximately 17 ft-lbs (23 Nm).
🎬 See this step-by-step 2013 Audi A4 alternator replacement

Related Parts to Replace

It is highly recommended to replace these parts at the same time as the alternator:

• Serpentine (Drive) Belt: If the belt is old, cracked, or glazed, it should be replaced. A new belt ensures the new alternator is driven effectively.
• Belt Tensioner: The tensioner pulley bearing can wear out, causing noise. The spring can also weaken, failing to provide proper belt tension. If the tensioner is original and has high mileage, replacing it is cheap insurance against future problems.
🎬 Watch: How to remove the serpentine belt

Frequently Asked Questions (FAQ)