Scratching intake sound

[jersey jok3r]

I've had this almost scratching sound coming from my intake system since I bought this car. The car runs fine and feels fine but the noise comes right when you put it in drive or reverse till about 3000 to 3500 rpm then goes away. Anytime the rpms drop under 3 the scratching sound comes back again. Any ideas what it is?

 

[dezldave961]

There's 2 usual suspects... one is the stock 3800 throttlebody's Idle Air Control (IAC) valve, since the design of the airflow through the IAC causes a scratchy intake sound, especially during cold starts.

The other cause might be the s/c coupler being worn out (assuming you have a GTP, judging by the 104 plugs). This is a $20-30 fix, and there should be plenty of articles either posted here, or on ClubGP's mod FAQ pages. Places like rollingperformance.com and ZZP sell the new/upgraded green coupler for a decent price.

- Dave

 

[jersey jok3r]

alright i'll check that out, yeh it is a gtp and I replaced the stock throttle body with a zzp throttle body so it must be the coupler thanks man

 

[dezldave961]

ZZP's ported and 78mm throttle body setups have the same IAC passage style, and will still sound that way. It's a noise usually amplified when an intake is added.

 

[Bio248]

its the IAC. the coupler sounds like rocks in a tumbler.

 

[boosting98]

^agreed. and u can definately tell where the noise would be. (passenger side)

 

[blueguy]

More like a shovel on concrete...but gravel works I guess.