Right try to explain !!

MY99

Traveling around 40 mph in 5th, give it some gas (plenty of pedal) to increase speed therefore under plenty of load and I get a sort of scraping rumbling metallic noise. Also does it in 4th if put under the same load factors i.e. very slow around 30mph then gas it.
Normal driving seems fine with no noises when speeds are increased.

Clutch??

 

Are you sure it is not detting (pinking) ???

that is the circumstances that you can induce it easily..

Do you have a knock link?

 

ps: I would change down and floor it rather than load up the engine like that btw..

 

I agree but when trying to increase speed slightly its not worth changing and flooring it.

Definitely not pinking sounds too harsh for that (if you see what I mean!)

 

Does it do it if you apply less throttle?

not just labouring the engine?

Such a nightmare trying to work out things without hearing them.. lol

 

imagine chugging along in 5th at aroud 40mph and tickling the throttle but if you bury the throttle it will pull through the noise.
Only seems to do it when warmed up also.

 

so the noise occurs on light throttle but not of full?

heat shield vibration and happens to be the resonance of it at that vibration?

or harsher than that?

 

Could be i will have a look at lunch

 

Occasionally my MY99 used to do exactly that for the first mile or so on my way home from work, as the engine was warming up. I got it when changing up to the next gear at around 2.5k rpm on a light throttle (maybe 20%), it never seemed to do it in the mornings though which i thought was weird. My MY99 was standard and running Optimax so det seems unlikely.

The only way i can discribe it was that it was a metallic scraping noise, like something metal rotating against something else metal without any lubrication, just at the point where the turbo was starting to cut in.

No idea what it was.

 

Thats a good desc. of the sound

 

Your not the only one who gets it, I do too.

I've been chasing it for two years and never got the bottom. The symptoms sound the same to me... It's most noticeable in fourth at 40 mph, on a flat throttle it'll rumble a little but if you drive through it the rattle noticeably intensifies, I get the same in third at the same revs.

I've had the waste gate checked, all the brake hoses around the bulk head and removed the uppipe/ downpipe heat shield but it's made no odds. In fact I've given up chasing it... My latest theory is that it's one of the heat shields around the manifold, when I took off the manifold to port it I noticed one of the bolts was missing but I was in a hurry to get it back on and haven't got around to checking it since.

Let us know if you get to the bottom of it!

 

Guys 40mph is to slow for 5th gear any car would do that sound , i will tell you the proper gear shifting in my STI :
1st Gear 12 mph maxiumm
2nd gear 25 mph
3rd gear 37 mph
4th gear 49 mph
5th 62 mph
6th 65+mph

thats for my driving Style any lower than that and you will have that unberailble sound the sound of steel ..

 

I should add, my P1 doesn't do it at all - touch wood.

 

Sorry for bringing an old thread up! But was doing a search on this type of noise as since the Sun has come out i have the windows open more and more, I noticed the type of noise as above.

Seems to only do it in 3rd and 4th I.E around 1700-2000RPM then goes away but at very slow speeds. (i.e load the engine) Doesnt do it in 1st or 2nd! Not that i have noticed anyway, i cant keep the revs that low or apply enough load without it gunning off to replicate the noise at these revs...

Am guessing heat sheilds are a common problem then?

Also guessing you shouldnt drive at 25mph in 3rd or 35 mph in 4th as this could cause det?

Bugeye - 2001

Cheers
Iain

 

Happens on mine too,just had decat done so probably is the heat shield.

 

Am getting mine de-catted this weekend so will get them to check the heatsheilds when they are removing the previous exhaust... hopefully just that!!