# Just changed serpentine, is this normal?

**URL:** <https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562>\
**Category:** Maintenance/Repairs\
**Created:** [March 21, 2025, 12:39am UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562 "2025-03-21T00:39:14Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Mpr2187\_193130](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@Mpr2187\_193130](https://community.cartalk.com/u/Mpr2187_193130)\
**Post date:** [March 21, 2025, 12:39am UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/1 "2025-03-21T00:39:14Z")

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Hey all,

I just changed the serpentine belt and I was wondering if these marks on the outside of the belt are normal. I used a Napa (gates) belt. First time using aftermarket, I usually use oem.

 ![IMG_2148](https://global.discourse-cdn.com/cartalk/original/3X/4/1/4154d06acd6b73acae87fba24c831ff10c2b9826.jpeg)

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**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [March 21, 2025, 12:45am UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/2 "2025-03-21T00:45:32Z")

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Did you check the idler pulley(s) for free and easy movement? Did the old belt look like this?

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [March 21, 2025, 12:48am UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/3 "2025-03-21T00:48:17Z")

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No. That’s not normal.

Check all the pulleys that contact the back of the belt. Like the tensioner pulley.

Tester

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<div class="post-metadata">

**Author:** ![Mpr2187\_193130](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@Mpr2187\_193130](https://community.cartalk.com/u/Mpr2187_193130)\
**Post date:** [March 21, 2025, 12:49am UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/4 "2025-03-21T00:49:24Z")

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So, the old belt did not look like this. It wasn’t shiny texture on the outside. Toyota belt was like a fabric on the outside. All pulleys seemed okay when I was under there.

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**Author:** ![Mpr2187\_193130](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@Mpr2187\_193130](https://community.cartalk.com/u/Mpr2187_193130)\
**Post date:** [March 21, 2025, 1:03am UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/5 "2025-03-21T01:03:45Z")

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All pulley’s move freely.

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**Author:** ![Rainflurry](https://avatars.discourse-cdn.com/v4/letter/r/cab0a1/32.png) [@Rainflurry](https://community.cartalk.com/u/Rainflurry)\
**Post date:** [March 21, 2025, 5:38pm UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/6 "2025-03-21T17:38:47Z")

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Are you positive that the belt is routed correctly? The marks on the smooth side of the belt are consistent with the smooth side of the belt contacting grooves of a pulley.

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**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\
**Post date:** [March 21, 2025, 6:35pm UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/7 "2025-03-21T18:35:41Z")

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Great point, @Rainflurry

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<div class="post-metadata">

**Author:** ![Mpr2187\_193130](https://avatars.discourse-cdn.com/v4/letter/m/59ef9b/32.png) [@Mpr2187\_193130](https://community.cartalk.com/u/Mpr2187_193130)\
**Post date:** [March 21, 2025, 8:08pm UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/8 "2025-03-21T20:08:44Z")

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Indeed it is. Belt is not coming in contact with the grooves. Only the smooth pulleys. I was thinking maybe it’s the material Napa used. It was a shiny gloss, not textured like Toyota.

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**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\
**Post date:** [March 21, 2025, 8:41pm UTC](https://community.cartalk.com/t/just-changed-serpentine-is-this-normal/199562/9 "2025-03-21T20:41:31Z")

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> [@Mpr2187\_193130](#):
>
> I was thinking maybe it’s the material Napa used. It was a shiny gloss, not textured like Toyota.

True, looks like a film wearing off the belt; normal.