Strange Grinding Noises When Cold

[gre03]

I’ve been hearing strange grinding noises from my gd3 since i got it a few years ago. They seem to happen when the car is cold and/or starts up after a long period (5+ hour’s approx) of being stationary. After a few minutes of low rpm driving the engine heats up and the noise goes away. For the time being I’m thinking it’s a fluid issue.

There are 3 types of grinding noises; one when I press the accelerator ¼ down, one when I press the clutch down and another when I release it, and one when I don’t accelerate and it’s just rolling.

The accelerator noise happens at about 2.5k+ rpm, it sounds like some metal is knocking on something. The clutch noise sounds like the clutch is sticking or not moving freely. The rolling noise sounds like the accelerating noise, but much louder and harder.

I can upload clips if it would help you understand the problem. I probably couldn’t take it to mechanic as it’s a very environment specific thing, and he probably wouldn’t hear anything.

Thanks

[bc143]

would it be the brake pad?(front) as i had my front pad done when my gd3 did 40k+ . the factory pad did grind day n night n sometimes unexpectedly. At first, I thought it was the wheel bearing, then found out by a good mechanic it just the brake pad and changed it for 80 including a Bendix pad.

[gre03]

what do you mean by 'grind'? Do you mean the squeaking noise made when your brake pads are worn out, and its just metal pressing on the discs?
The noise doesn't happen when I'm braking, only when I'm accelerating, decelerating, and using the clutch.

[beeza]

Need some clips mate.

[gre03]

Need some clips mate.

sure thing. I'm at work at the moment, so I'll record some on the way home.

[beeza]

Good good :)

[gre03]

hmm had a go at recording the sound with my iphone by putting it in the front console drink holders, with the mic facing up. i thought this would get the clearest engine and pedal noises.
turns out my dad put high octane fuel in it recently, and now i can't hear the noise :S
i suppose this solves the problem, but when i run low on fuel again, i'll take another recording and see if the noise is still there.
not sure how rpm and fuel levels would result in the noise, but then again i don't know that much about the mechanics of cars.

thanks for the help beeza. i'll get back to ya when i have a solid recording of the sound.

[beeza]

Ahh,sounds like your car needs 98 octane fuel,ask 'aaron',he's an expert on this!

:)

[bc143]

good but instead of guessing should we take it to a mechanic to hv a look?

[beeza]

Unless your really concerned about it,there's no need.

If the noise comes back post a video up!

[aaronng]

The GD3 shouldn't require 98 Octane as it is requires 91. You can test with one tank of 98 just to see if the noise goes away. Otherwise, I also recommend taking it to a mechanic.

[gre03]

well turns out the fuel has nothing to do with the noise. figured out that it happens when the engine/gearbox winds down and the accelerator is pressed just a bit. leads me to believe it may be a gearbox issue.
i've given up on trying to record the sound, as the jazz is too well sound-proofed to get a reasonable recording.
only way i could think of getting a mechanic to fix it, is leaving it at the shop overnight and showing him the noise when it starts up cold. is it safe to do this?
cheers