How to Replace the Serpentine Belt on a 2016-2018 Audi A6 (Accessory Drive Belt) (Engine: Inline 4 2.0L)
Step-by-step belt routing, tensioner release, required tools/parts, and key torque specs
How to Replace the Serpentine Belt on a 2016-2018 Audi A6 (Accessory Drive Belt) (Engine: Inline 4 2.0L)
Step-by-step belt routing, tensioner release, required tools/parts, and key torque specs for 2016, 2017, 2018
🔧 A6 - Serpentine Belt Replacement
The serpentine belt (also called the accessory drive belt) spins key accessories like the alternator and A/C compressor. Replacing it is mostly about safely releasing the spring-loaded belt tensioner, removing the old belt, and routing the new belt correctly.
Difficulty Level: Intermediate | Estimated Time: 0.7-1.5 hours
⚠️ Safety & Precautions
- ⚠️ Work on a cool engine; hot coolant parts can burn you.
- ⚠️ Keep fingers and tools clear of the belt path; the tensioner is spring-loaded and can snap back.
- ⚠️ Do not start the engine with hands/tools near the belt.
- ⚠️ If you raise the car, support it with jack stands before going underneath.
- ⚠️ Battery disconnect is not required for this job, but keep the key away from the car to prevent an accidental start.
🔧 Required Tools
You'll need the following tools for this repair:
- 16mm combination wrench
- 16mm socket
- 3/8" drive ratchet
- 3/8" drive long handled breaker bar
- Serpentine belt tool (specialty)
- Torx T25 screwdriver
- Torx T30 screwdriver
- Flat trim removal tool
- Floor jack (rated 3-ton minimum)
- Jack stands (pair, rated 3-ton minimum)
- Wheel chocks
- 17mm socket
- 1/2" drive torque wrench (20-200 Nm range)
- Mechanic gloves
- Safety glasses
- Flashlight
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Serpentine belt (accessory drive belt) - Qty: 1
📋 Before You Begin
- Park on level ground, set the parking brake, and install wheel chocks behind the rear wheels.
- Open the hood and let the engine cool fully.
- Take a quick photo of the belt routing before removal. If a routing sticker is present under the hood, use it.
- Tip: Lay the new belt next to the old.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove top covers for access
- Pull up to remove the plastic engine cover by hand (it’s held by rubber grommets).
- Use a flat trim removal tool as needed to gently lift corners without cracking the cover.
- If the front intake snorkel/duct blocks access, remove its fasteners using a Torx T25 screwdriver or Torx T30 screwdriver (varies by duct), then lift it out.
Step 2: (Optional) Improve access from the right-front wheel area
- If you can’t comfortably reach the belt tensioner from above, raise the front-right corner using a floor jack and support it with jack stands.
- Use a 17mm socket to remove the right-front wheel bolts and remove the wheel.
- Use a Torx T25 screwdriver to remove the lower splash shield/liner screws needed to see the belt area.
- When reinstalling the wheel later: Torque to 120 Nm (89 ft-lbs).
Step 3: Locate the belt tensioner and relieve belt tension
- Find the belt tensioner (a spring-loaded arm with a pulley). A “tensioner” is the part that keeps the belt tight automatically.
- Place a 16mm socket on the tensioner’s hex (use a 3/8" drive ratchet or 3/8" drive long handled breaker bar for leverage).
- Slowly rotate the tensioner to relieve tension. Keep steady pressure—don’t let it snap back.
- Tip: A serpentine belt tool fits tight spaces best.
Step 4: Remove the old belt
- While holding the tensioner released, slip the belt off the easiest-to-reach top pulley (commonly the alternator pulley).
- Slowly let the tensioner return to its resting position.
- Remove the belt from the remaining pulleys and pull it out of the engine bay.
Step 5: Inspect pulleys before installing the new belt
- Spin each accessible pulley by hand and feel for roughness or grinding.
- Check for wobble (side-to-side movement) and for coolant/oil leaks near the belt path.
- If any pulley is noisy or wobbly, don’t continue until the underlying issue is repaired (a bad pulley can shred a new belt quickly).
Step 6: Route the new belt correctly
- Route the new belt around the pulleys following the under-hood routing diagram (or your photo).
- Make sure the belt ribs sit perfectly in the grooved pulleys.
- Leave one easy-to-reach pulley for last (so you can slip it on while the tensioner is released).
Step 7: Re-apply tension and seat the belt
- Use the 16mm socket with the 3/8" drive ratchet or breaker bar to rotate the tensioner again.
- Slip the belt fully onto the final pulley, then slowly release the tensioner.
- Do a final visual check: the belt must be centered on every pulley, not hanging off an edge.
Step 8: Reinstall removed panels and components
- Reinstall any splash shield/liner screws using a Torx T25 screwdriver.
- Reinstall the wheel (if removed) using a 17mm socket, then lower the car and torque to 120 Nm (89 ft-lbs) using a 1/2" drive torque wrench.
- Reinstall the intake snorkel/duct using a Torx T25 screwdriver or Torx T30 screwdriver.
- Press the engine cover back down into its grommets by hand.
✅ After Repair
- Start the engine and let it idle for 30-60 seconds while you watch the belt (keep loose clothing/hair away).
- Listen for chirping/squealing. If heard, shut off the engine and re-check belt alignment on every pulley.
- Turn on the A/C briefly and confirm normal operation (no belt noise).
- Recheck visually after a short test drive to confirm the belt is still centered.
💰 DIY vs Shop Cost
Shop Cost: $180-$350 (parts + labor)
DIY Cost: $30-$80 (parts only)
You Save: $150-$270 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.5 hours.
🎯 Ready to get started?
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