Why is my brand new serpentine belt still squeaking?
A brand new serpentine belt can still squeak during startup, acceleration, or after driving in the rain. This ongoing noise prevents drivers from resolving the issue with a simple belt replacement alone, often requiring them to investigate pulleys, tensioners, or alignment.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 10.9× more often in r/MechanicAdvice than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Waiting for the belt to dry or go away by itselfDid this help you?
- 2Spraying the belt with silicone spray to diagnoseDid this help you?
- 3Replacing the belt and tensioner togetherDid this help you?
- 4Inspecting and replacing faulty tensioners or pulleysDid this help you?
- 5Cutting the belt off and starting the car to look for the rattling pulleyDid this help you?
- 6Taking things apart to self diagnoseDid this help you?
- 7using deodorant on the beltDid this help you?
- 8using a stretch-to-fit beltDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Just replaced the serpentine belt (brand new) and it is still making this noise. The old belt burned up on the ac pulley and broke. There is kind of a rattling noise.”source ↗
“It’s a 2012 Honda Accord 4cyl with 250k+. Trying to see if it’s worth fixing / if it is something I can do DIY.”source ↗
“Had my serpentine belt replaced as I thought that was the issue. But not even a month after replacement it is squeaking again.”source ↗
“Happens when I turn on my car and when I accelerate. But after a while driving it STOPS making noise.”source ↗
“After driving in the rain yesterday my serpentine belt started squeaking. Is it as simple as I need to replace the belt?”source ↗
“the belt seems to squeak every time I rev the engine or have it above idle while driving I can see it moving on the water pump pulley.”source ↗
Where this came up
People with this problem also raised
- 10Drove several miles with a snapped serpentine belt, did I ruin my engine?
- 7Engine still squeaking after replacing water pump and tensioner
- 8Why is my car suspension popping after replacing struts and springs?
- 3Can't get the serpentine belt back on the alternator pulley
- 2Why does my garage door still squeak after lubricating it?
- 34Grinding noise after installing new brake pads and rotors