Nasty noise coming from the front underside

[mopower]

Hey Nico Techs,

I'm hearing this nasty noise coming from the underside of my manual 93 240sx coupe.It sounds like a croak croak sound when you're inside the car, but hearing from the outside, it sounds more of an 'khouk, khouk' like something's grinding or scratching..When I let the car roll and going down a drive way, that noise appears at that certain angle as well. At speeds higher than 15mph, you don't hear it.Also, when rolling, AFTER braking semi-hard, the noise will appear again.

I thought they were my springs/shocks, so I replace those, but still there.Then I thought it was something to do with power steering, so I added more fluid, noise still there.

Then I noticed something really strange, the noise only comes out when the car is warmed up and driven for about 5 mins. The noise is not there during cold weather.

Is there a component under the car that when heats up, it makes this nasty noise?

T.I.A.

[LayNLow240]

Check to see if your brake pads are still good, and have a brake shop check to see if the brake rotor is warped.

[SR24DET]

it sounds like your heat shield. is it a raddling. If thats the case just take it off

[mopower]

Thanks for the response you guys.

I will check the brakes this weekend. How can you tell if the rotor's warped?

As for the rattling..do you mean something is loose? Where is this heat shield located exactly?

ty

[180fan]

if the rotor's warped, you'd feel a pulsation in the brake pedal when you depress it.

heat shield at the catalytic is a common culprit. right under your driver seat.