Sorry to bring this issue back from the dead but I can't seem to get rid of this "moo" sound. Sounds exactly like a boost leak but my car boost perfectly.

Symptoms: Occurs during light accelerating between 2000-2500 rpm but if I increase throttle it goes away. Also occurs when I left go of the throttle and coast down.

What I've tried: The rubber door stop method with 4 holes drilled into it.

Ironically this occured straight after I had my muffler change to a "quieter" one which leads me to believe that I've had this problem for a long time but because the car was so loud, I couldn't hear the "moo" over the top of the exhaust.

Any suggestions on what to do next?

 

Ok could this be the reason why? My holes are too big?

 

moooooooooooooooooooooooooooooooooo !!!

check ur **** under the car. maybe something exhaust back is hitting a heat shield or something.

 

yea try a lilttel smaller holes and make sure its not going ON the airpump but rather the metal line that runs out from behind the UIM.....the ACV

 

try ONE hole about that size. i remember on the M2 intake box, the line for connecting the airpump bypass (the long metal tube) was about the size of a quarter, and the hole for the air to pass though was about 1/4" in diameter

 

You beauty problem solved! I reduced the number of holes to 3 and made the diameter alot smaller than those current ones and the problem went away.

Thanks again guys.

 

I honestly dont understand how this works for everyone but me i bought a pack of chair caps 7/8 literaly did the smallest holes by stabbing it with a very small screw driver attatch it to the little tube next to the intake manifold with a clamp and it still mooo's !! do i have to cover the air pump aswell or something? could someone please help me?

 

I was lame and had a breather filter on my air pump and when I removed it the mooo went away.

 

k well i got rid of my moo sound but only by blocking the hole close to the intake manifold and also the one on the air pump. right now my question is.. is it bad to block the hole on the airpump ? i notice that it sucks in air but by blocking it with a chair cap i'm able to eliminate the moo sound could someone please help me?

 

I Have the moo sound too and damn it's loud and annoying!!!! >_<
I didn't understand about the holes, you mean should I block the way from intake to airpump?

Which holes to block? please...

 

All- just to put some closure on this issue. I also had added the 'Dale' drilled chair cap to my RX...didn't work.

Reduced the multi holed cap with a new cap with just 1 1/4 hole in the middle, mooing is dead :-)
Hope this helps someone