This procedure covers the removal and replacement of the serpentine belt idler pulley on the 2.5L I4 engine in 2016-2024 Hyundai Tucson AWD models.

Warnings

Tools required

Parts

• Idler pulley assembly × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely for at least 2 hours
3. Open hood and secure with prop rod
4. Photograph serpentine belt routing diagram (located on radiator support or underside of hood)
5. Verify replacement idler pulley matches original in diameter and bolt pattern

Procedure

1. 1

   Remove engine cover
   Locate the plastic engine cover on top of the 2.5L engine. Pull upward firmly on the cover to disengage the mounting grommets. Some models may have 10mm bolts securing the cover - remove these first if present. Set cover aside.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
2. 2

   Locate the idler pulley
   Identify the idler pulley on the front of the engine. The 2.5L I4 typically has the idler pulley positioned between the alternator and the crankshaft pulley on the passenger side of the engine. The idler pulley is a smooth pulley (no grooves) that only guides the belt.
   ℹ️Do not confuse the idler pulley with the tensioner pulley - the tensioner has a spring-loaded arm while the idler is fixed
3. 3

   Release serpentine belt tension
   Locate the belt tensioner assembly. Using a 15mm wrench or serpentine belt tool on the tensioner bolt, rotate the tensioner clockwise (toward the passenger side) to relieve belt tension. This will create slack in the belt. Have an assistant help if available, or use a breaker bar for additional leverage.
   ⚠The tensioner spring is very strong - maintain firm control of the tool to prevent sudden release that could cause injury
4. 4

   Remove serpentine belt
   While holding tension released on the tensioner, slip the serpentine belt off the idler pulley first, then off one of the larger pulleys (alternator or crankshaft recommended). Slowly release tensioner pressure. Remove the belt completely from the engine bay and inspect it for cracks, glazing, or excessive wear.
   ℹ️If the belt shows signs of wear, now is an ideal time to replace it along with the idler pulley
5. 5

   Remove idler pulley bolt
   Using a 14mm socket and ratchet, remove the single bolt securing the idler pulley to its mounting bracket on the engine block. The bolt threads into the engine front case. Hold the pulley with your other hand as you remove the bolt to prevent it from falling.
   Torque spec

   Idler Pulley Bolt45 Nm (33 lb-ft)
6. 6

   Remove idler pulley
   Pull the idler pulley straight off the mounting stud or bracket. Inspect the mounting surface on the engine for any debris, corrosion, or damage. Clean the mounting area with a clean rag if necessary.
   ℹ️Spin the old pulley bearing to check for roughness, noise, or resistance - this confirms whether replacement was necessary
7. 7

   Install new idler pulley
   Position the new idler pulley onto the mounting bracket, ensuring it sits flush against the engine block mounting surface. Verify the pulley spins freely without binding or excessive play before securing.
   ⚠Ensure the pulley is properly aligned on the mounting stud before installing the bolt to avoid cross-threading
8. 8

   Install and torque idler pulley bolt
   Install the idler pulley bolt and hand-tighten until snug. Using a torque wrench, tighten the bolt to 45.0 Nm (33 lb-ft). Verify the pulley still spins freely after torquing.
   Torque spec

   Idler Pulley Bolt45 Nm (33 lb-ft)
9. 9

   Reinstall serpentine belt
   Following your belt routing diagram or photo, route the new or existing serpentine belt around all pulleys EXCEPT one (typically the alternator or idler pulley is left for last). Ensure the ribbed side of the belt contacts all grooved pulleys properly.
   ⚠Incorrect belt routing will cause immediate damage - verify routing matches diagram exactly before applying tension
10. 10

    Tension and seat serpentine belt
    Using your wrench or belt tool, rotate the tensioner clockwise again to create slack. Route the belt over the final pulley, ensuring all ribs are properly seated in all pulley grooves. Slowly release the tensioner to apply proper tension to the belt. Verify the belt is centered on all pulleys.
11. 11

    Reinstall engine cover
    Position the engine cover over the engine, aligning the mounting grommets with their posts. Press down firmly until all grommets are fully seated. If your model has bolts, install and tighten to 16.0 Nm (12 lb-ft).
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)

Reassembly

1. Double-check that serpentine belt is properly seated on all pulleys with ribs fully engaged
2. Verify belt routing matches factory diagram exactly
3. Confirm all tools have been removed from engine bay
4. Ensure engine cover is securely fastened

Verification

• Start the engine and listen for any unusual squealing, chirping, or rubbing noises from the belt area
• Observe the serpentine belt while engine is running at idle - it should track centered on all pulleys without wobbling or slipping
• Check that the new idler pulley is rotating smoothly without wobble or noise
• Rev engine slightly (1500-2000 RPM) and verify belt remains stable and quiet
• After initial test, shut off engine and recheck belt alignment on all pulleys
• Test drive vehicle and verify no belt-related noises under acceleration or accessory load

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