Recently my 07 fit has started to make a pulsing sound at 70-80mph. Thus far I have determined that it is from the exhaust. If I put my car into neutral at 75mph it goes away (even if maintain speed). Also, if I drive in 4th or 3rd gear at the same rpm range, but not at 70+, it does not make the noise. It's about a pulse per second.

Its really just an itritating sound. My only idea thus far is to clean my K&N filter. (The car has that and an aftermarket cat back exhaust.)

Any other ideas? Ive done lota of mechanic work and this is a new experience for me.

 

Pulsating sounds always point me towards parts of the car that are spinning, starting with the tires. Years ago I had a bad rear tire (a bubble forming on the inside sidewall) that made my Hyundai Accent sound like a Mustang GT.

From the exhaust side of things, get your car up in the air and try to move the exhaust by hand, looking for loose/broken hangers or heat shields that could be vibrating. However, if your noise was caused by resonance/vibration in your exhaust you would expect it to be tied to RPM rather than speed, in which case you would also expect the noise in other gears at the same RPM.

 

Do you have any window even slightly open ?

 

This is a good question. It is unbearable (=pulsating/throbbing sound) in my Fit with one window cracked.

 

You won't want to hear this, but the only solution is to close the window.

 

Definitely not that! 😂

 

Thanks. Although I was born in a barn, it wasn't yesterday... I was able to figure this out all by myself. Now if I could just figure out my velcro shoes.