For some reason when deceleratin i get a scrapin metal noise from my gsr only at 3500 rpm? Sometimes it happens at higher rpms to when deceleratin but It consistently happens at 3500rpm... My friend thinks its my cat? I had a listen and it does sound like its comin from the bottom of the car... What the hell?

 

So, are saying that it's RPM dependent? If so then... I wouldn't think it's your cat. What does it sound like? A highe pitch screeching? or what?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 95IntegraLSR &raquo;</TD></TR><TR><TD CLASS="quote">So, are saying that it's RPM dependent? If so then... I wouldn't think it's your cat. What does it sound like? A highe pitch screeching? or what?
</TD></TR></TABLE>Yeah, it sounds like a screeching, kinda like a belt.... Its stange how it only happens at 3500 rpm though...

 

So it is a screech not a rattle? If rattle could be header/heatshield.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redGSRguy &raquo;</TD></TR><TR><TD CLASS="quote">So it is a screech not a rattle? If rattle could be header/heatshield. </TD></TR></TABLE>More like a screech... not a rattle really

 

check your header for exhaust leaks, my friend had this noise once only in lower rpms but in high rpms it went away.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thrty8street &raquo;</TD></TR><TR><TD CLASS="quote">check your header for exhaust leaks, my friend had this noise once only in lower rpms but in high rpms it went away.</TD></TR></TABLE>Cool, is it easy to take off the heatshield? What is the best way to check for a leak and what would i do about it?

 

check all the bolts, or nuts around the header. make sure they are all tight. Also try starting the car when its cold and feel around with your hand around the header where it bolts the head and check to see if you feel any air.

 

Another way to check for leaks, is to take some throttle body cleaner and spray it down in the TB, after you have taken the heat shield off, and you'll be able to see the exhaust leaking, because of the burn off from the TB cleaner. MY friends dad has a big shop and did that one day. it worked.

 

sounds like one of the heatshields is rattleing, usually happens at a lower rpm like you stated, could be the exhaust manifold or the cat heatshields. I would take exhaust manifold heatshields off then drive it to see if the problem persists

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UNDERGROUNDAUTOSALON &raquo;</TD></TR><TR><TD CLASS="quote">sounds like one of the heatshields is rattleing, usually happens at a lower rpm like you stated, could be the exhaust manifold or the cat heatshields. I would take exhaust manifold heatshields off then drive it to see if the problem persists </TD></TR></TABLE> Yeah someone else told me this too... Its does seem to come from under the car tahnks!