Hi, recently my 2017 Honda Fit started making a hissing noise on the driver's side of the engine. It only happens after driving on the freeway for about 20 minutes. It lasts for maybe 30 seconds. It comes back after another 15-20 minutes. Also, I noticed that if I push on the brake, it changes the pitch of the sound.

Does anyone have an idea of what this is? I'm just wondering if it's urgent for me to bring it in or if it can wait...or maybe something I can fix myself. Thank you.

 

Welcome. Any noise from the front end which changes as you apply the brakes makes me think there is mechanical friction involved somewhere within the braking system. So it could be warped rotors, or perhaps a caliper that is hanging up. No way to know, needs further evaluation.

You didn't mention how many miles on your vehicle. If you're due for your first brake job, typically what you will hear is a screeching metal-on-metal sound, and feel a pulsing, as the pads wear to nothing. Those are the built-in wear bars that signal end-of-life for the pads.

Can you wait? I wouldn't. Anytime brakes are suspected, I suggesting taking it in asap. They are your primary safety system, so you want to keep them as functional as you possibly can.

 

Thanks! That's very helpful. It has 63,927 miles on it.

This wouldn't be a powertrain issue right? That's all that's covered by my warranty at this point.

 

Powertrain? Doubtful. They tend to fail more spectacularly without necessarily giving a lot of symptoms first.

63K would be pretty early for pad replacement unless you ride your brakes hard. More likely warped rotors. This happens more than you think in case of temperature swings, especially if they happen often and quickly.

When the rotors warp, they make a scraping sound as they contact the pads when they're not supposed to. At higher frequencies - i.e., highway speeds - this starts to resonate, and of course, the frequency of that resonance will change with the rotation changes induced by tapping the brakes. That could be your hissing noise.

 

I would assume you've done the basics and checked your tire pressures. And checked the cover under the engine to make sure it hasn't come loose.and is dragging on the road periodically..And checked radiator level to make sure you haven't lost coolant hissing out of the radiator cap. etc

 

Ah okay. Thanks. That makes a lot of sense.

 

Thanks. I know the tire pressure is good. I'll check the other things.

 

I brought it in. It needed new break pads and rotors. Thanks for your help.

 

Excellent, glad it worked out for you.