Serpentine belt keeps coming off

2007 NISSAN PATHFINDER

150,000 MILES

AGLHOLLYWOOD

MEMBER
1 POST

First time it came off I inspected the belt and it appeared fine. The idler pulley has a slot it fits in when you tighten it l, so I know it's not loose. Is it possible the belt is stretched out and needs replaced? Or what else could be causing this?

Feb 7, 2019 at 4:52 AM

SCGRANTURISMO

✓ASE Certified Mechanic
4,897 POSTS

Hello,

What happens with serpentine belt tensioners is over time they get bent or the spring inside of them gets weak. This allows the serpentine belt to come off due to misalignment. Here are a couple of helpful links:

https://www.2carpros.com/articles/how-a-serpentine-belt-tensioner-works
https://www.2carpros.com/articles/serpentine-belt-tensioner-replacement

I have included step by step instructions for your vehicle in the diagrams below. Installation is the reverse of removal.

Thanks,
Alex
2CarPros

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Feb 7, 2019 at 9:57 AM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.