How to Replace the Serpentine Belt on a 2018 Kia Optima (Accessory Drive Belt)
Step-by-step instructions with required tools, belt routing tips, safety precautions, and wheel torque specs for 2016, 2017, 2018, 2019, 2020
How to Replace the Serpentine Belt on a 2018 Kia Optima (Accessory Drive Belt)
Step-by-step instructions with required tools, belt routing tips, safety precautions, and wheel torque specs for 2016, 2017, 2018, 2019, 2020
š§ Optima - Serpentine Belt Replacement
The serpentine belt (accessory drive belt) turns key accessories like the alternator and A/C. On your Optima, replacement is mainly about safely accessing the belt and rotating the spring-loaded belt tensioner to slip the belt off and on.
Difficulty Level: Intermediate | Estimated Time: 0.8-1.5 hours
ā ļø Safety & Precautions
- ā ļø Work on a cool engine; hot pulleys and coolant lines can burn you.
- ā ļø Keep fingers clear of the tensioner and pulleys; the tensioner is spring-loaded and can snap back.
- ā ļø Support the car with jack stands; never rely on a floor jack alone.
- ā ļø Remove the key/fob from the car so no one can start it.
š§ Required Tools
You'll need the following tools for this repair:
- Safety glasses
- Mechanic gloves
- Wheel chocks
- Floor jack (rated 2-ton minimum)
- Jack stands (rated 2-ton minimum)
- 21mm lug nut socket
- 1/2" drive breaker bar
- 1/2" drive ratchet
- 3/8" drive ratchet
- 3/8" drive extension set
- 10mm socket
- 12mm socket
- 14mm socket
- 17mm socket
- Torque wrench (10-150 ft-lbs range)
- Trim clip remover (specialty)
- Flashlight
š© Required Parts
HowToo sells all the parts you need for this repair:
- Serpentine belt (accessory drive belt) - Qty: 1
š Before You Begin
- Park on level ground, shift to Park, and set the parking brake.
- Chock the rear wheels using wheel chocks.
- Open the hood and locate the belt routing diagram (usually on a sticker in the engine bay). If itās missing, take a clear photo/sketch of the current routing before removal.
- Pro tip: Take a quick phone video of the belt path.
šØ Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the right front wheel for access
- Use a 21mm lug nut socket and 1/2" drive breaker bar to slightly loosen the lug nuts (about 1/2 turn) while the tire is still on the ground.
- Lift the right-front using a floor jack at the proper jacking point, then support with jack stands.
- Remove the lug nuts using a 21mm lug nut socket and 1/2" drive ratchet, then remove the wheel.
- Reinstall later: Torque to 88-107 Nm (65-79 ft-lbs).
Step 2: Remove the splash shield / access panel
- In the right-front wheel well, remove the plastic clips using a trim clip remover (specialty).
- Remove any small bolts using a 10mm socket and 3/8" drive ratchet.
- Peel back or remove the access panel/splash shield enough to clearly see the belt and tensioner. Use a flashlight.
Step 3: Identify the belt tensioner and the release point
- Find the automatic belt tensioner (itās a spring-loaded arm with a pulley). āAutomaticā means it holds belt tension by spring forceāno manual adjustment bolt.
- Look for the hex head/bolt on the tensioner arm used to rotate it (common sizes on this Optima are 17mm socket or 14mm socket).
Step 4: Release belt tension
- Place a 17mm socket on the tensioner hex and attach a 1/2" drive breaker bar. If the 17mm doesnāt fit, switch to a 14mm socket.
- Rotate the tensioner smoothly to relieve belt tension (youāll feel strong spring resistance).
- While holding the tensioner rotated, slide the belt off the easiest-to-reach smooth pulley (often an idler or the alternator pulley) with your free hand.
- Slowly let the tensioner return to its resting position. Pro tip: Never let it snap back.
Step 5: Remove the old belt and compare it to the new one
- Remove the old belt from all pulleys by hand and pull it out through the wheel well opening.
- Compare old vs new belt length and rib count (they should match). Use your flashlight for a clear look.
Step 6: Route the new belt (most important step)
- Route the new belt around the pulleys exactly like the under-hood routing diagram.
- Make sure the ribbed side sits fully in the grooves of ribbed pulleys, and the smooth side rides on smooth pulleys.
- Leave the easiest pulley for last (usually a smooth idler pulley) so you can slip the belt on after releasing tension.
Step 7: Apply tension and seat the belt
- Rotate the tensioner again using the 17mm socket (or 14mm socket) and 1/2" drive breaker bar.
- Slip the belt onto the last pulley, then slowly release the tensioner.
- Visually confirm the belt is centered on every pulley. Use a flashlight and check from multiple angles.
- Pro tip: One mis-seated rib will shred the belt.
Step 8: Reinstall the splash shield and wheel
- Reinstall the splash shield/access panel using a 10mm socket and 3/8" drive ratchet.
- Reinstall all clips using a trim clip remover (specialty) as needed to press them fully in.
- Reinstall the wheel and hand-thread lug nuts.
- Lower the car, then tighten lug nuts in a star pattern using a torque wrench and 21mm lug nut socket: Torque to 88-107 Nm (65-79 ft-lbs).
ā After Repair
- Start your Optima and let it idle while you watch the belt for 30-60 seconds (it should run smoothly with no wobble).
- Listen for chirping/squealing. If you hear noise, shut the engine off and re-check belt alignment on every pulley.
- If the old belt showed cracking/glazing, inspect the tensioner and idler pulleys by spinning them by hand (engine off). Any roughness or wobble means the pulley/tensioner should be replaced.
š° DIY vs Shop Cost
Shop Cost: $160-$320 (parts + labor)
DIY Cost: $25-$60 (parts only)
You Save: $100-$260 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.8-1.2 hours.
šÆ Ready to get started?
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