2023 Nissan Altima Serpentine Belt: Routing, Replacement, and Part Numbers

Quick Answer

• Belt Length: Varies by engine (see below)
• Rib Count: 6-rib
• Engine Options:
  • 2.5L 4-Cylinder (PR25DD engine):
    • OEM Belt PN: Nissan 11720-6CA0B
    • Gates Cross-Ref: Gates K060805
    • Dayco Cross-Ref: Dayco 5060805
    • Continental Elite Cross-Ref: Continental Elite 4060805
    • Auto-Tensioner PN: Nissan 11955-6CA0A (Gates 38446, Dayco 89446)
    • Idler Pulley PN: Nissan 11925-MA000 (Gates 36173, Dayco 89043)
  • 2.0L VC-Turbo 4-Cylinder (KR20DDET engine):
    • OEM Belt PN: Nissan 11720-6MA0A
    • Gates Cross-Ref: Gates K060710
    • Dayco Cross-Ref: Dayco 5060710
    • Continental Elite Cross-Ref: Continental Elite 4060710
    • Auto-Tensioner PN: Nissan 11955-6MA0A (Gates 38448, Dayco 89448)
    • Idler Pulley PN: Nissan 11925-MA000 (Gates 36173, Dayco 89043)

Belt Routing

The 2023 Nissan Altima utilizes a single serpentine belt to drive multiple accessories. Before attempting to remove or replace the belt, always take a clear photograph of the existing belt's routing path. This will serve as an invaluable guide during reinstallation.

Here's a general text-based routing path. Keep in mind that exact pulley locations can vary slightly between the 2.5L and 2.0L VC-Turbo engines, so your photo is crucial.

General Routing Path:

1. Begin at the crankshaft pulley (the largest pulley, typically at the bottom center of the engine).
2. From the crankshaft, the belt typically runs up to the A/C compressor pulley.
3. From the A/C compressor, it will often go to a smooth idler pulley.
4. From the idler pulley, it will route to the alternator pulley.
5. Next, the belt wraps around the power steering pump pulley (if applicable – some Altimas have electric power steering, eliminating this pulley).
6. From there, it will engage the water pump pulley.
7. Finally, the belt goes to the automatic tensioner pulley, which maintains the correct belt tension. The belt then returns to the crankshaft pulley to complete the loop.

How to Replace the Serpentine Belt

Replacing the serpentine belt on a 2023 Nissan Altima is a manageable task for the DIY mechanic, provided you have the right tools and follow proper steps. This job typically requires a serpentine belt tool or a 3/8-inch drive breaker bar.

1. Safety First: Ensure the engine is off and cool. Disconnect the negative battery terminal to prevent accidental starts.
2. Locate the Tensioner: Identify the automatic belt tensioner. It will have a square opening for a 3/8-inch drive tool or a specific point for a serpentine belt tool.
3. Relieve Tension: Insert your serpentine belt tool or breaker bar into the tensioner's square opening. Rotate the tensioner to relieve the belt tension. This will allow you to slip the old belt off the pulleys.
4. Remove Old Belt: Once tension is relieved, carefully remove the old belt from all pulleys. Pay close attention to its routing if you didn't take a photo.
5. Inspect Pulleys: While the belt is off, inspect all pulleys for any signs of wear, wobbling, or excessive noise when spun by hand. Replace any worn idler pulleys or other components as needed.
6. Route New Belt: Refer to your photograph or the general routing description above. Carefully route the new serpentine belt around all pulleys, leaving the tensioner pulley as the last one to engage.
7. Apply Tension: Again, use your serpentine belt tool or breaker bar to rotate the tensioner, allowing enough slack to slide the new belt onto the tensioner pulley.
8. Release Tensioner: Slowly release the tensioner, ensuring the belt seats correctly in all pulley grooves. Double-check that the belt is properly aligned on all pulleys.
9. Reconnect Battery & Test: Reconnect the negative battery terminal. Start the engine and observe the belt for a few minutes to ensure it runs smoothly without any wobbling, squealing, or misalignment.

Replacement Interval

Nissan generally recommends inspecting the serpentine belt at regular service intervals, typically every 30,000 to 60,000 miles, and replacing it as needed. Factors such as driving conditions, climate, and engine type can influence the belt's lifespan. It's good practice to visually inspect your belt for cracks, fraying, or glazing every oil change.

Signs of a Failing Belt or Tensioner

Ignoring a failing serpentine belt or tensioner can lead to significant issues, as these components drive critical engine accessories. Here are common warning signs:

• Squealing or Chirping Noises: This is often the most common sign of a worn, loose, or misaligned belt. It can also indicate a failing pulley bearing.
• Visible Cracks, Fraying, or Glazing: A visual inspection will reveal a worn belt. Cracks on the ribbed side, fraying edges, or a shiny, glazed appearance indicate it's time for replacement.
• Loss of Power Steering: If your power steering suddenly becomes stiff, especially at low speeds, the serpentine belt may have slipped or broken.
• Overheating Engine: The water pump, driven by the serpentine belt, circulates coolant. If the belt fails, the water pump stops, leading to engine overheating.
• Battery Not Charging / Dashboard Warning Light: The alternator charges the battery; if the belt breaks, the alternator stops working, and your battery will eventually die. A battery warning light on your dash will illuminate.
• A/C Not Working: The air conditioning compressor is belt-driven. If the belt fails, your A/C will stop blowing cold air.
• Wobbling or Vibrating Tensioner/Pulleys: A failing tensioner might wobble excessively while the engine is running, or its arm may not maintain consistent tension, leading to belt slippage.
• Grinding Noises from Pulleys: Worn bearings in idler pulleys or other accessories can produce grinding or groaning noises.

If you notice any of these symptoms, it's crucial to inspect your serpentine belt and related components promptly to prevent further damage.

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