I just bought a used 2003 G35 sedan and it's making a couple wierd noises. I wanted to check if anyone can relate so I know what I'm looking for. First off, on occasion it makes a very obvious scraping noise from underneath the vehicle. I tried testing braking during the noise to see if it effected it but it did not. Also, i'm getting a humm from the rear of the vehicle when on the highway at higher speeds. I'm thinking it may be the differential or drive train for the second noise. I'm concerned that both of these noises could turn into problems down the road if the necessary maintainance isn't done. The car has 102,500 miles. Thanks.

 

The scrapping sound could be the front underbody panel falling off lol. Look underneath do you see anything hanging?

 

I don't think that's it, i've heard it before, it's like a distinct squeeking noise. It goes skskskskiiiiiiii!!!! I tried braking during it and it didn't effect it. And it's on and off, wierd huh?

 

When it comes to that rear differential humm? do i need to change the differential fluid? I'm going to anyway.

 

^ I am not sure about that at all, Only thing I knew, I posted :O I am sure others will reply soon.

Try finding the service records of the car. Go ahead and change the diff fluid out, the drain plug is a magnet so you can see if theirs lots of crap on it. I would go with Amsoil SVG Diff Fluid, its one of the best

 

Is the noise like a screeching sound or a scrapping kind of sound? Because if it's a screeching sound it could also be your brakes. And if it's a scrapping sound just get on your knees and look underneath the front of your car and take a good look to see if the underbody panel is probably loose.

 

I'll check it out, it sounds mechanical, I don't know the exact terms but i think it may possible steering components wearing out. I'm going to have a mechanic do an all out inspection.

 

might be that squeaking creeking nose, if that is the case then its ur compression rods, it's time to change them!

 

It's a good idea to have a mechanic check out a used car before you purchase it, especially one with high miles. Get it to a trusted one to perform an all inclusive inspection. It would be a good idea to replace all fluids unless you have records they have been changed recently.