2006 wrx, 106K miles (issue was present before 105K maintenance).
vf39 w/ supporting mods and protune
Stock clutch
Swepco 201 in the transmission, changed around 20k miles ago.

I only get the sound with the clutch disengaged (pressed in) while giving the engine a little gas. As it revs up/down, you can hear the sound. The sound only occurs for the first 5-10 minutes after a cold start.

Here is the video


Any help is greatly appreciated!

 

sounds like rod knock...

 

Uh.. I'm no mechanic, but that doesn't sound like a rod knock. Could be wrong..

 

oh? what do you think it is?

 

Throwout bearing? How many miles on the clutch?

 

I don't think rod knock would just go away 5-10 min after the car is started

 

yes it would.. most of rod knock I've heard are from cold start. When it makes the noise warm, it's pretty much when the bearing is gone..

 

begin signs of rod knock can be heard during start when cold. low oil pressure and cold parts cause it. the video sounds like a bad bearing or possible some form of air leak. cant really tell. but it doesnt sound like throwout bearing or rod knock

 

Sorry didn't see all the replies here. Definitely not rod knock. The sound is only present with clutch disengaged. I can rev it slightly after a cold start (like in the video) and the sound will not be there. Normal driving in gear does not produce this sound either except between shifts while disengaging clutch and the rpms are falling.

Doesn't seem to be a throwout bearing issue based on the demonstrations I've watched on youtube. I showed the video to my tuner and he didn't know what it was but assured me it wasn't a problem with the clutch.

Clutch is original, 107k miles. No slipping and does not feel abnormal.

 

My car made a similar sound, ended up being washer and bolt was loose on driver side bumper to fender.

Not saying yours is the same but i would try to locate the general area were the noise is coming from and check for loose things

 

That would be great if it was easy as that! But since it goes away after the car warms up, I'm thinking that isn't the case. Thank you for your input though!

 

Was the timing belt tensioner replaced during the 105k?

 

Yes, timing belt tensioner was replaced. The sound started a couple thousand miles before my timing belt service.