Lexgendboi

iTrader: (1)

Lately, i have a problem with my car. It started to make weird noise as the car is rolling.(it's on and off noise pattern frequency depended on the speed of the vehicle)The noise isn't something like road noise nor wind. It sounded like the brake pad were in contact with the rotor at an instant then off, then again...but i noticed the car isn't shaking or anything as i hit on the brake at high or low speed(indicated the rotor isn't "bend" due to the water got on it while it's hot). I didn't have this problem when i first put on my new wheel. Now the tire is about 12,000 miles then this noise started to get annoyed. Though the tire isn't wear much. Does anyone here experienced this problem?

DIrEctQL

Possibly rotor is warped. What you described sounds identical to my warped rotors. I am not the only one who has this problem and breaks on SC300 and N/A Supra are known to develop such a problem with breaks. These breaks weren't meant for our cars (our cars are very hevy). To somewhat fix the problem upgrade to Supra TT breaks.

Red93sc400

If your rotor was warped, you will very likely feel a throb or pulse in the brake pedal when you apply the brakes. You can use a dial indicator and check the rotor to insure that it is running true. This is done with a magnetic dial indicator on an arm. You have to check both surfaces of each rotor. A mildly warped rotor could exhibit some noise without a pulse.

A more likely possibility is that one of your caliper's cylinders is intermittantly stuck or hanging in the engaged position. This can cause a range of symptoms from a mild noise to even a big bouncing shudder that feels almost like a flat tire at speed. Also make sure your anti-squeal springs are all in. These apply outward pressure to your pads in a slight manner. If one is missing or weak the pad will drag on the rotor which will glaze the rotor.

A third possibility is that you did mention new wheels. You should see if your new wheels are not bent in any way. If you hit a pothole, then you could have whacked a wheel.

Another possibility is that the rear parking brakes are hanging up in the engaged position. They are located inside the rear rotors. They are NOT self adjusting and are a mild pain in the *** to adjust.

Yet another possibility is that the low brake pad sensor is starting to scrape one of your rotors. Check the pad depths.

Another one that is you may have one or more loose lug nuts on your wheels. After they are installed, you are supposed to torque the lugs to a specified measure. Then within on week you are supposed to recheck the torque. Especially on new wheels as the wheel can flex and wander. So check those lugs to make sure they are still snugged up to spec.

You should try this test. On a quiet street bring the car up to speed and with your hands off of the wheel but close to it, apply the brakes. The SC400 should come to a stop as straight as an arrow with no pull at all. If the car pulls right or left start your inspection of the brake parts on the side it pulled towards.

The above test assumes your car is aligned well and rolls straight without input from your hands on the wheel. If it is not in alignment, then forget this test. BTW, the SC400 has both front and rear alignment of wheels.

ohioboy

Your problem may be as simple as cupped front tires. That would make a noise at SOME speeds like snow tires or a grinding brake or bearings grinding. Take the car to a rep. tire dealer and they can FEEL the tire surface to tell if it is cupped. These cars are famous for cupped tires on the front (since they are rear wheel drive) if you are not **** about rotating every 3000 to 5000 miles. This is a very inexpensive test to do first!

trebien

If it sounds like a pad with rotor contact, I would say:

Low Wear indicator on brake pads.

Worn return springs on brake pads.

Possible stuck cylinder problem, or even something being stuck on surface of pad. Can you see any major scratches or ridges on the rotor (front and back) that go all the way around?

Lexgendboi

iTrader: (1)

Thankyou all for the inputs guys...My pads are still in good shape, i am thinking the problem is more likely to be warp rotors. Because the prob sorta started since i have the car wash with high pressure hose after 15-20 minutes driving the car. I ordered a set of X drilled rotors already, once they got here, i'll put a conclusion to this. If the new rotors don't fix the issue, then i might have to thinking of my tires. ( Eversince i drop my ride down 1" with 18" wheels, i had my wheels alignment done right after, but the Toyota dealer didn't do a right job, all of my tires appeared to have negative camber. They all worn out excessively on the inner side of the tires. I took it back to them, they rework on it and said because i lowered the car with bigger wheels, they won't be able to make it to the exact spec....So now the only thing i can do is drive and check back in time to see how the tire wearing off. That's suck isn't it...) what an option to read huhhh

VQT

Are you sure your pads are in good shape? You need to take the pads off to see, especially the inside one. I had the same problem a few months back. The brake caliper was faulty and the inside pad wore out more than the out side one. Result in out side pad look OK, inside all wore out to the metal.

amati5

According to the owner's manual, when the pads are worn to certain level, they generate some sort of a warning sound. If i am not wrong, it's a high pitch sound. I know this may not be the case since you said your pads are still ok.

Speaking of weird noise, i have this "rattle" sound at 30 mph when my foot is off the gas pedal. I can't feel any vibration though, or maybe it's there but minimal. My mechanic said it's the tires and i don't believe him. I had this noise even before i changed my tires. I's driving my me nut

VQT

Maybe you need to exercise the engine more often. With 5 miles driving to work every day and traffic lights on top of it.

Anyway, more detail on rattle sound? Could it be a bolt loose on the muffler piping? I had the rattle sound on my 93 Prelude, its turn out to be a loose bolt on the muffler pipe.

amati5

It's definitely not from a metal part, more like rubber or plastic and come from the middle or front part of the car. I shoud add that, it'll go away in the summber

VQT

Does it happen when the car under light load and only at certain mph? When you step on the gas and it doesn't happen when coasting(sp). Also, doesn't vibrate under heavy load (accelerate fast)?
When was the last time you change the trans. fluid?

amati5

At 30mph (moving up from 25) and only when my foot off the gas, rolling or braking. Spent $175 flush out the trans fluid, no luck. I hope it's not the drive shaft that got a loose bolt. I weight 135 lbs and rarely have a passenger, so can't tell. You've got some clues ?

Actually it's interesting since you mentioned it, when i had my wife drive it and i was on the passenger side trying to detect where the sound come from, it was subtle. Same when i tried to tell my mechanic (again, he was driving and i was on the passenger side).

jkwong

HI have a 1992 SC400. I have been having problems with the brake pedal. When I depress the brake pedal I get a whistle sounding noise. What is the problem? I changed brake pads not too long ago and the brakes are good. Any help?