Alright, the car is a 97 Si ( SOHC) Mods are, Intake, cam Gear (0 degrees right now) and cat-back.
And now the problem........ I have a noise when I come up around 3K I seem to notice it mostly in 3rd gear, mainly beacuse I think this is the time when I usualy comin up on RPM slowly, as apposed to lower gears. Anyway the sound is as best I can describe... a slight knock I guess, it does not seem to be directly related to the engine speed meanign that it does sound as fast as the engine is going. I woudl say it is more from the driver side. as I pass 3k .. it does not get worse or louder, and gets hard to hear over exhaust and regualr engine noise.

I have checked the plugs for signs of anythign and they show to be buring great, the performance is fine, car is not buring any oil, and there does not seem to be any thing wrong at other RPM's

So the question is ... what do ya goT !!!

 

bump

 

does the noise happend on every gear??

 

Whens the last time you got a valve adjustment?

 

sounds like a rattling heatshield on your exhaust somewhere. i (and 9000 others) have the same problem. the car just makes a funny noise at 3000rpm.....

 

yea me too, i think it comes from the exhaust (some where between header and the cat)...

the noise come out at 3000 rpm... i will notice it the best when i shift down gear from 4 to 3 or from 3 to 2....

also sometimes in the highway on fifth gear, i wanna reduce the speed and remove my feet from the gas pedal, so the rpm goes down from 5000 rpm to 4000 rpm then to 3000 rpm, the noise come out... but after 3000 rmp to 2000 rpm, it's normal again

i always wanna know why that happens too...

 

the werid thing is it won't have any noise when i pick up the speed...
no matter fast or slowly

 

same problem here......but mine sounds like a METAL-on-METAL grinding sound

 

could be a tranny bearing. is it a rattle or like a whine?

 

actually i could feel like the rpm doesn't come down smoothly at 3000 rpm....
other than that, it's normal

just only when i reduce the speed
the sound is so hard to describe... since i am not a native eng speaker
let me ask my friend and see wut's the sound explain in word

it's not metal sound

 

I doubt it's a heatshielf. It's been my experience that you normally only hear a rattling heatshield near the driver's seat in 1st.

See if you can find a digital camera with a microphone and get a soundclip.

 

alright well there are a lot people that have told me to check the heat sheilds, So I am gonna have to try that.

Yes it does make it in all gear, when I am crusin in 5 th aroud (110 km) or so which is like right on 3K I dont' seem to hear it as much, I do not seem to hear it in down shifts, although I do get a nice Buzz from waht I am almost positive is my heat sheild right under seat. And as for gettin a sound clip well that would be kinda hard ,it only seems to do it when driving if I rev the engine at a stand still, it is there but not exactly the same sound.

As for the Valves, I adjusted them back at the end of summer and then I took it into the shop and checked them again last week just to make sure it wasn't that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by clm &raquo;</TD></TR><TR><TD CLASS="quote">I doubt it's a heatshielf. It's been my experience that you normally only hear a rattling heatshield near the driver's seat in 1st.

See if you can find a digital camera with a microphone and get a soundclip.</TD></TR></TABLE>

um... in my case i will try to make a soundclip... i dun think the problem come from the engine... since this is the new swap and it has the compression 240 all the way...

but the tough part of sound clip is that the engine and muffler sound very loud and might not hear the werid noise
but when you sit there and drive it, you must notice... sometimes even the passager won't notice as well
anywayz...

 

Actually, now that I think about it more, the mid/rear heatshield rattled a little bit. It may have been closer to 3000 RPM. It was kind of a "clanging" noise IIRC.

 

when i got a new exhaust put on they took off the stock ball and joint flexible part right after the stock downpipe. However when they put the new exhaust back on they just welded it on instead of using the flexible ball and joint thing. Well anyways since they just welded it on it doesn't allow the exhaust to flex like it did before and so at 3k my rpms would stall for a bit. i took it back and made then reweld it so that the engine sits normally. it helped the sound but it didn't go away completely. now that i have the turbo on it's open downpipe and there is no sound. there was also now sound when my header got disconnected from my cat ( the weld broke ) If you still don't understand then here's the quick version. when they put ur exhaust on they had to movfe the header pipe back and then weld it on. this caused the eninge to tilt forward a tad and makes the noise at 3k because of this.