Mechanics

GRINDING

2001 Nissan Sentra • 4 cylinder Automatic • 86,000 miles

While driving, the car makes a grinding noise that lasts as long as it takes to shift gears from lower to higher as I increase my speed. In other words, the noise starts just before the RPM peak and ends just as the RPM drops. It also gets worse after having been driven on the interstate for an extended period of time. Overdrive is always on.
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Ibealion
March 19, 2011.



Is it a grinding sound or could it be a ratteling sound? Can you tell aprox where the sound is coming from?

My wife describes it as a rattle so let's say yes, it is a rattle.
It sounds like it's coming from the driver side or maybe the middle. Definitely not from the passenger side.

Tiny
Ibealion
Mar 20, 2011.
This may sound too simple, but take a rubber mallot and tap on the exhaust system to see if you can duplicate the sound. Often times, a heat shield, resinator, or even the inside of the catalytic converter can come loose and you will hear something as you described. Most of the time, you will hear it at different RPM's.

There is a distinct rattle when I tapped on the exhaust system under the car but it sounds very different outside the car and it isn't loud enough to be heard inside the car.

Tiny
Ibealion
Mar 20, 2011.
Okay, when the engine is running, it could make that rattle a lot louder. Can you identify where on the exhaust the sound is coming from? Check for loose/rusted muffler clamps, check the heat shields on the catalytic converter as well as the resinator if you have one. If they are tight, see if the noise is coming from inside the catalytic converter or resinator. They can come loose inside and cause noise and partial plugging.