Noise question!

Hello! – I have a 2001 Nissan Altima GXE and recently it has been making a scratching noise when I drive it at highway speeds. I noticed I mainly here it when I am stepping on the gas pedal to accelerate, but as soon I as take my foot off, the noise disappears. I can’t duplicate the sound when I want but it does occur enough to become a nuisance, and something that I am worried about.



I should also mention that this sound only started happening after I had new tires installed a few weeks ago. However, when I brought it back to the mechanic, they did not see anything wrong. They also put the car up on the lift and tried to duplicate the sound, but nothing happened.



I have also noticed that I hear the sound more frequently when the weather is hot, and it seems to completely disappear when it gets cooler during the evenings.



If you have any suggestions, please feel free to leave a comment. At this point, I’m at a complete loss to what could be the issue. Thank you.

I would have a general muffler shop look over the exhaust system. What you may be hearing is a heat shield rattle. This is not life-threatening to the car but can be an aggravation to listen to.

Most heat shield rattles can be easily repaired so if you by chance get hit with a high estimate to replace this, that, or the other, then you should back up a bit and find someone else to look this over.

It may be that the exhaust system was inadvertently tweaked by the lift when the tire shop installed the new rubber.

A simple DIY test can be easily done if you want to try it. While it’s not always 100% definitive it’s worth a shot.
Wrap an old towel or heavy rag around the tailpipe. Now ball your fist up and whack the rag with the side of your fist. Many times if a heat shield rattle is the problem, this smacking of the tailpipe will verify it by causing a rattle that can be heard.
Hope some of that helps.

Thanks for the tip! I will give that a shot before heading into the shop. Hopefully it’s not pricey like you mentioned.