Nissan 370Z Forum - Scraping sound when not scraping

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Scraping sound when not scraping

So we all know what it sounds like when the little plastic pieces that hang down scrape the road. I'm getting that sound even when I hit little itty-bitty dips in the road that only cause the suspension to rebound less than an inch. It feels like something is hanging down like the cover underneath and it is catching every bump. But when I look under the car... nothing. I checked the sway bar in the front to see if anything was loose. No evidence that was the problem. The rear sway bar appears to be fine. No other suspension mods were done. No exhaust mods. No wheels. No spacers. No springs. Nothing.

So what on earth could cause me to hear and feel the scraping under my feet? It is much more pronounced with a passenger. But I went for a long drive yesterday with a passenger and didn't hear it very much at all. But then today I hit a smooth dip in the road and it sounded like I bottomed out when before this was never a problem.

Is this the sound of a blown shock? Because I've been having a problem with the front left one making a swishing sound over some heavier bumps where the shock unloads too much. But this sounds like it is coming from directly underneath the car or maybe as far over to the right side. Unfortunately my hearing isn't good out of my right ear so its a pain to locate the source.

Any ideas? I'll be taking it to the dealer tomorrow if I can't figure out a way to correct the issue myself. But I'd really like some opinions here first so maybe I'll have some ammo when the dealer comes back and tells me everything checks out.

Thanks in advance for useful responses!

take off the front left wheel and see if the shock is leaking anywhere...

your description sounds like a blown shock

Rog. I'll check it out. Thanks.

Are you lowered? Tire scraping inside of fender or fender-liner?
You can put some painter tape up in there and see if the tire scuffs it.

Could be that annoying little front mud flapper. I took mine off and made a BIG OL DIFFRENCE.

nope. Not lowered. And that's the thing. I know for a fact I'm not scraping. These are little itty bitty bumps and it still makes that sound. But I can feel it too. It hits the entire chassis. Leads me to believe it is a suspension component. We'll see. Got an appointment at the dealer in a few minutes.

It was the front tires. Who knew?! They apparently don't like the roads here. Can't blame them. Guess it's time for new wheels/tires! :tup:

I'm taking mine in for the sound I'm hearing..

so. Dealer said it was the tires causing the noise. Had four new tires put on a few days later with an alignment. Still hearing it. And if anything, its getting worse. If I hit a little rough spot in a parking lot (still flat without any real dips) it'll still make that grinding sound.

I'm beginning to wonder if it could possibly be the stock end link bearings. Or the sway bar bushings. They've been on for 17,800 of the 17,880 miles that are on this car. Never bothered with relubricating them since it's only been 8 months and I had sway bars on another car with the same type of bushings that never wore out even after 3 years. Could those parts cause this sound?

It's also more prevalent when another person is in the car. But if I'm the only one and I've been driving awhile it fades a bit and will only occur over larger bumps and dips.

Any ideas? Anyone?

rear differential bushings? Is there a wet mark on your differential?

Endlinks are a clunk. Sway bar bushings is a "creaky door" kind of noise. "Grinding" makes me think metal-on-metal. Have you gotten the car in the air and looked for any shiny spots where something is rubbing when the suspension compresses?

I'm trying to get it on a lift this afternoon sometime. But both the nissan dealer and merchants said everything looked solid under there. I even watched them as they looked at every single part. Oh. And to be specific, it's the front passenger side area.

Maybe the backing plate is touching the brake rotor? Get that corner up in the air, take the wheel off and bend the plate back some. See if that works.

will do. Thanks for the suggestion.

Not a problem. I just can't think of too many other places where you can get metal-to-metal contact. If you were complaining about squeaking, clunking or creaking it would be easier to narrow down.