Mazda3 Belt noise

mazda
belts

#1

I’m having a problem with my 2012 Mazda3 (automatic, non-skyactive model) that others seem to be complaining about on the online forums, but there seems to be no consensus.

About 10,000 miles into owning the car, it started making a sort of high-pitched gargling sound when I accelerate and the tachometer reads 1500-1900 RPMs. At first, the sound occurred sporadically when I was accelerating under these conditions, but now, at 28,000 miles, it’s happening almost every time I accelerate between 1500-1900 RPMs. Here are a few more facts:

The engine must be warm
The car must be in drive (I cannot replicate it in neutral or park)
The sound occurs regardless of whether the AC is on

I took it to the dealer 3 times. The first time, they changed the belt, and that helped for about 1000 miles. The second time, they told me that the noise is normal, and I should not worry. The third time, I took it to a different dealer, and they put a “dressing” on the belt. That helped for about 600 miles. Now the sound is back again, and it’s driving me nuts. It definitely doesn’t sound normal. If I test drove a car at 28,000 that made this sound, I definitely wouldn’t buy it.

I’d appreciate any suggestions.


#2

Sounds like one of the pulleys is the culprit, although im not sure why it wouldnt make the noise in park, i guess being in drive loads it down more?

I think its possible to remove the belt and run the car for a little bit to see if the noise goes away, but lets wait and see what other comments say.


#3

Belt dressing ??? I threw out my can of it 30 years ago. That dealer put it on to get you out the door hoping you won’t come back. I don’t know the belt setup on your car, but if everything is run on one serprntine belt, I would see if all the pulleys line up.
Then take the belt off and make sure all the pulleys turn smothly.
Next replace the belt and if it still squeals, replace the tensioner.


#4

You seem to have established the problem is belt related.

As a general rule once belt dressing is used you have to start over. The belt must be replaced and the pulleys cleaned with solvent.

Pressure test cooling system to be sure no antifreeze is leaking onto the belt.


#5

Thanks everyone for the comments. You’ve been very helpful. I’ll take it back and have them check the pulley and tensioner. And I’ll ask them to replace the belt, since it sounds like the dressing ruined it. I’ll update this post when I learn more.

It’s still under the bumper-to-bumper warranty, and this being my first new car, I’m noticing that getting anything done under warranty is like pulling teeth. I almost can’t wait for the warranty to run out so that I can finally get something fixed!


#6

The belt is a wear item and likely not covered.