2016 Mercedes-Benz Sprinter — Serpentine Belt Routing & Length

Quick Answer: 2016 Sprinter Serpentine Belt

The 2016 Mercedes-Benz Sprinter was available with two primary diesel engine options in North America, the 2.1L 4-cylinder (OM651) and the 3.0L V6 (OM642). The serpentine belt and related components are different for each engine. Always verify part numbers with your VIN before ordering.

For the 2.1L 4-Cylinder Diesel (OM651)

• Belt Length & Rib Count: Approximately 2020 mm, 7-rib
• OEM Belt PN: Mercedes-Benz A0039937296
• Aftermarket Belt Cross-References: Gates K070795, Continental 4070795, Dayco 5070795
• Auto-Tensioner PN: Mercedes-Benz A6512001170
• Idler Pulley PN: Mercedes-Benz A6512000470 (smooth), A6512020019 (grooved)

For the 3.0L V6 Diesel (OM642)

• Belt Length & Rib Count: Approximately 2010 mm, 7-rib
• OEM Belt PN: Mercedes-Benz A0019938196
• Aftermarket Belt Cross-References: Gates K070791, Continental 4070791, Dayco 5070791
• Auto-Tensioner PN: Mercedes-Benz A6422001370
• Idler Pulley PN: Mercedes-Benz A6422020919 (there may be multiple idlers)

Belt Routing

Before you remove the old belt, we strongly recommend taking a clear photograph or drawing a diagram of the belt's path. The routing is different between the two available engines.

2.1L 4-Cylinder (OM651) Belt Routing

The belt snakes through the accessories in the following order:

1. Starts at the Crankshaft Pulley (at the bottom).
2. Goes up and around the Alternator.
3. Down to the grooved Idler Pulley.
4. Around the A/C Compressor (if equipped).
5. Up to the smooth Idler Pulley.
6. Wraps around the Power Steering Pump.
7. Over the Water Pump.
8. Finishes by looping under the Tensioner Pulley.

3.0L V6 (OM642) Belt Routing

The V6 has a slightly different path:

1. Starts at the Crankshaft Pulley.
2. Goes right to the A/C Compressor.
3. Up to the smooth Idler Pulley.
4. Across and around the Alternator.
5. Down to the Power Steering Pump.
6. Across to the Water Pump.
7. Finishes by wrapping over the top of the Tensioner Pulley.

How to Replace the Serpentine Belt

To replace the belt, you must first release the tension. On both engines, the automatic tensioner has a specific location to attach a tool.

For the 2.1L I4, you will typically use a 17mm socket on a long-handled ratchet or breaker bar to rotate the tensioner clockwise to release tension.

For the 3.0L V6, you will often use a large Torx bit (such as a T60) or a specific serpentine belt tool with a pin to fit into the tensioner body. Rotating the tensioner clockwise will relieve the pressure, allowing you to slip the belt off a smooth pulley, like the water pump or an idler.

Once the old belt is off, carefully route the new belt around all the pulleys according to your photo or diagram, leaving a smooth pulley for last. Double-check that the belt's ribs are properly seated in the grooves of every grooved pulley. Apply pressure to the tensioner again, slip the belt over the final pulley, and slowly release the tensioner, ensuring the belt stays aligned.

Replacement Interval

There is no fixed replacement interval from Mercedes-Benz for the serpentine belt. It is considered an "inspect and replace as needed" item. As a general rule of thumb for a commercial vehicle like the Sprinter, a belt should be inspected at every oil change and proactively replaced every 60,000 to 90,000 miles to prevent an unexpected failure. The tensioner and idlers should be inspected at the same time and typically replaced every second belt change, or sooner if they show signs of wear.

Signs of a Failing Belt or Tensioner

Listen and look for these warning signs that your serpentine belt system needs service:

• Squealing or Chirping Noises: Often heard on startup or during acceleration, this is the most common sign of a worn or glazed belt.
• Visible Wear: Inspect the belt for cracks, fraying, glazing (shiny surface), or missing ribs.
• Tensioner Noise: A rumbling or grinding noise coming from the tensioner pulley indicates a failing bearing.
• Tensioner Vibration: With the engine running, watch the tensioner arm. If it is vibrating erratically or rapidly jumping, the internal spring mechanism is worn out.
• Pulley Misalignment: Look down the path of the belt. All pulleys should be spinning on the same plane. A failing tensioner or idler bearing can cause a pulley to wobble or sit at an angle, which will quickly destroy the belt.

If you're not comfortable tackling this job yourself, you can find a trusted and certified shop in your area on Repairius.