Sixdown

I've recently noticed weird metallic scraping sounds coming from under the car somewhere or maybe in the engine when I drive at around 1800rpm.

Every time I accelerate to 1800, the scraping sounds starts, but once I pass 1900 it ends. It only happens when accelerating, not when decelerating. The noise is quite loud from the outside, and barely heard inside. It's like metal cutting against metal.

Could it be the driveshaft or a heatshield? The transmission shifts smoothly, and the noise occurs no matter what gear the car is in.

Sixdown

Any ideas at all to what the problem could be? Its a metallic rubbing sound.

EXE.UCF10

iTrader: (3)

Check your brakes. Sounds like it might be a seized caliper. First look to see if there's any shiny/metallic dust on your wheels (from the brake caliper grinding out your rotor). If there isn't any, inspect the brake caliper and pad.

Sixdown

I just checked all my brakes last week when I rotated the wheels and changed the oil. I noticed nothing wrong, and why would it happen only between 1800 and 1900 rpm, only when accelerating, not cruising.

EXE.UCF10

iTrader: (3)

I can't explain why it only happens between 1800-1900 rpm...I'm just sharing my experience and what my problem was because it sounds very similar to what you're going through.

Sixdown

if it is the caliper, how would you fix it anyway?

jcrome04

is there anywhere in your area that does free brake inspections?

PureDrifter

iTrader: (10)

you replace the caliper....rebuilding would cost more than a cheap caliper from a junkyard.

mind you, if it makes this noise when the car is standing still its obviously not going to be a brake issue...

EXE.UCF10

iTrader: (3)

A friend of mine (he's a mechanic) just took out the piston and lubed it up with some sort of special grease and slid it back in...and that did the job.

mobilyte

iTrader: (3)

does it sound like a metal coffee can with a coin inside being shaken? my LS makes the same sound, i remember once hearing another LS driving make the same sound. happens as i accelerate past ~1400 rpm, i couldnt duplicate the sound with the car on a lift. this leads me to believe it might be the tranny mount rather than a heat shield.

btw, you can get a caliper seal rebuild kit for less than a single rebuilt caliper. the kit, sold at the lex dealership or most auto part stores, will service both sides of either the front/rear brakes.

Sixdown

its not really like coins in a coffee can because the sound is smooth and pronounced, not rattling. Its like a circular saw cutting through metal, which now sounds to me like the calipers as some people said. Thanks everyone for your help. I'll go and check the calipers myself. Why would it happen at only 1800rpm?

Sixdown

update: I checked the calipers and nothing was wrong with them. None of them are frozen or anything, and I replaced the rotors at the same time.

I drove the car again so that I could hear the metallic sounds and then stopped the car at a light, put it in neutral and revved to 1700.
Guess what, the scraping sound started again all the way up to 2000 rpm. So it cannot be the driveshaft or a heatshield. It is coming from the engine bay.

Could it be the engine mounts or a loose valve or something else?

raSCal

Did you ever resolve the issue? My 98 SC is making the same noise, both when idling after first turned on, and when accelerating at low RPM.

cation

Does your car do this only when it's below a certain temperature outside?

My P/S pump is leaking onto my alternator and when it's below say 30°F outside I will get a high pitched metal on metal scraping sound (like a bad bearing). I believe I have it diagnosed as my alternator bearings or my serpentine belt tensioner bearing. I say this because one really cold morning when I fired up my car I heard the sound which before only occurred at certain RPMs (1700-2000) under load. I popped the hood and determined that the sound was coming from the P/S pump and alternator area. I'll be replacing the P/S pump and alternator next weekend once my new P/S pressure hose gets in, so I will follow up if this provides the fix to the problem.

python

iTrader: (4)

maybe your clutch fan hitting something when u accelerate