Matt300ZXT

iTrader: (2)

I was driving my 98 SC300 the other day and it sounded like when I was just giving it enough gas to roll out of the driveway in the morning, it sounded like there was a slight scraping kind of noise that sounded like it was coming from the front passenger caliper, but went away once I was going above 1 or 2 mph, and did it again when I was backing out of my spot at work later that day. Only did it at very very very low speed, and when I put it in drive to move forward at a crawl, it felt like the caliper was sticking here and there because it barely hung up/lurched forward. I assumed it was the caliper sticking due to being old or a bad line, so I went ahead with the LS400 front and SC400 rear calipers/rotors. I had been wanting to do all the brakes for a while and figured it was time.

Anyways, today I go to drive it and the same thing. Now it's a bit more frequent and easier to pinpoint what it feels like and where it's coming from. The feeling I was getting this evening is, when sitting at idle at a redlight in drive (automatic car of course), it sound like there was a light scraping/grinding noise, almost like when brakes are real bad and you're just stopping from a crawl. And when I was in a line of cars at an on ramp and could only move a little at a time until it was my turn, a time or two it felt like it wanted to shudder if I was just giving it enough gas to crawl forward. However, when leaving a light if I give it a little gas and just go (not peeling out or anything) it's not a problem. It only seems to present itself when I'm sitting in idle (in drive), or when I give it the tiniest amount of gas just to roll forward a car length or two. If I just go then it doesn't do it.

Also, I noticed while sitting in the drive through tonight getting food on the way home, when I had it in drive it made the scraping/grinding noise here and there, but if I just put it in park there was no problem. So it's only doing it while in drive, and while sitting and waiting, or ever so slightly crawling forward.

I'm wondering if maybe the rubber doughnut that connects the driveshaft together (assuming it's a 2 piece shaft) is worn out and the 2 shafts are wanting to turn at 2 different speeds at a crawl until I get up and just go. It shifts fine, runs just fine at speed and all that, it's only doing it while idling in drive or crawling forward or backward.

Matt300ZXT

iTrader: (2)

Anyone care to take a shot at it?

msc300

Grinding while driving sounds like a wheel bearing if you replaced brakes and rotors already

Ramblerman

Could be a wheel bearing, jack the car up at each wheel and roll the wheel to see if you hear any noise or feel roughness in the bearing. Check your drive shaft for any abnormal wear and look for anything making contact that should'nt be.

LEXXIUM

iTrader: (1)

It's totally normal man, don't sweat it, both of my rides have ls400 brake upgrades in the front and stock rears I get the same pad click on both cars when putting the car in the reverse, but as far as grinding and scraping noise, i would take tires off and inspect all the work as far as brake caliper to the hub bolts, make sure the calipers are properly grinded and installed on the right side, check all your caliper pins and pad and rotor wear needs to be looked at for sure to see what the grinding is from.
it could also be your calipers not retracting back and need rebuild