macbook pro touch barThe MacBook Pro, complete with Touch Bar.salchuiwt/Flickr (CC)

Apple customers say there’s a strange new problem affecting some MacBook Pros: They’re making a “popping” noise.

As previously reported by 9to5Mac, numerous people are complaining online that the new 15-inch MacBook Pro with a Touch Bar, released in 2016, is making the weird sound.

It’s not exactly clear what’s causing the issue. Some are pointing to heat as a possible cause, noting it happens when their laptops are under stress.

“Mine only exhibits the popping sound when it warms up under processor load, then I don’t hear it again until it cools down,” one user wrote on Apple’s support forum in a discussion about the issue. “I concur, I think it’s to do with expansion and contraction somewhere in the body of the casing.”

Another said that when they took their device in to Apple’s Genius Bar customer service team, a dent on the bottom of their MacBook Pro was blamed, and they had to pay $130 to get it fixed. But others say their devices are popping even when there’s no dent present.

Just behind the MacBook Pro logo, on the other side,” another user said. “When the Mac is heating up, without pressing, its pops exactly here too.”

One MacBook Pro owner told Business Insider it happens “multiple times a day. Notably when i open the laptop — usually after about 30ish seconds, but not every time. And then every 20-100 minutes after that.” It’s about as loud “as a trackpad click,” they said.

The problem seems pretty widespread, but — while annoying — it doesn’t seem to be causing more serious issues for people affected. Their laptops are just occasionally making popping noises. It’s possible that it’s symptomatic of a deeper developing hardware issue — but right now, it’s just not clear.

There’s a few videos online of the popping noise, like this one:

 

An Apple spokesperson did not provide comment at the time of publication.

Is your MacBook Pro making a popping noise? Get in touch: rprice@businessinsider.com