scraping-grinding noise - Honda Prelude Forum

nuro · 02-02-2002, 08:35 AM

Today was the first real day of spring here so for the first time i'm driving with windows down, sunroof open

I noticed a wierd metallic grinding-scraping noise as i acellerate. It doesnt happen in neutral, it only seems to happen in third and fourth and at around 3000-4000 RPM. But only if u gas it. So if youre crusing along, its fine, then you hit the accelerator (get a little jerk cuz of the torque) and griiiiiiiiiiiiiiiiind. It takes a while to go away.

Anyone have ANY idea what might be going on here? Is this some drivetrain noise that i should just not worry about? Its not really loud, but its noticeable.

Thanks,
(a worried) Nuro

Joon525 · 02-02-2002, 08:50 AM

Is your car modified?

nuro · 02-02-2002, 10:45 AM

i just got my car a couple weeks ago. all it has on it is H+R springs

Joon525 · 02-02-2002, 11:00 AM

...but on my car the cause of the noise was the aftermarket header. I'm wondering if some bolt on the exhaust system is loose and vibrating in the rpm range you specified. Before I fixed my problem the noise occurred at about 3000 rpm.
Does your noise happen in every gear in that range but more so when in 3rd or 4th gear?

nuro · 02-02-2002, 11:03 AM

I couldn't tell in 1st and 2nd, but its def. noticeable in 3rd and 4th. you get it every time you tap the gas in 3k to 4k RPM in these gears... not lower, not higher. and the noise will stay through the first couple seconds of your acceleration.

Joon525 · 02-02-2002, 11:10 AM

Quote:

Originally posted by nuro
I couldn't tell in 1st and 2nd, but its def. noticeable in 3rd and 4th. you get it every time you tap the gas in 3k to 4k RPM in these gears... not lower, not higher. and the noise will stay through the first couple seconds of your acceleration.

EXACTLY what my car was doing. There seems to be a lot of turbulence in that rpm range.
To be more specific.....there's a flange on the header that bolts up to the engine block that's supposed to be for support. On my car the flange broke/cracked and in that rpm range it was vibrating against the block and thus making that noise (again only at about 3000 rpm).

Go under the car can just check to see if any bolts are loose before you bring it in to have it looked at. I'm not saying this is definitely the problem but it's worth it to check.

nuro · 02-02-2002, 12:26 PM

im no mechanic but can you describe what this flange is, where it is, etc? maybe so i can do it myelf or at least explain it to my mechanic before i pay $$ for him to look around...

thanks

btw, you dont think that this could cause any other problems? i can still drive the car hard, right?