Tapping from intake when secondaries are closed (with video)

[rigol2000]

Hello all, I have a 95 MTX. When I am at idle, I notice a tapping noise from my intake. The tempo of the tapping increases with the engine RPMs. When the secondaries are opened, the tapping stops. I assume this is from the butterflies, but I know I could be wrong. I have a video with sound that may give you a little more to go on. In the video, I open and close the secondaries so you can hear the difference.

Follow this link: VIDEO

Thanks,
Chris

 

[sho'd]

yes this is the butterflies makeing that noise, now how to adjust them, or make them stop is another story, i have never had to deal with it, so i can't give you the solution, only my best diagnosis of the problem, there are quite a few guys on here that will chime in and tell ya what to do.

 

[AREA 91]

Sounds normal to me. If you want to double check them, un plug the secondary accuator on the rear of the intake while it's running. The butterfly's will open, and the noise will stop. No need to rev the engine this way, and get it confused with injectors/timing chain, being RPM related.

 

[sho'd]

in his video he is unplugging the secondary, i think, looks like it. i believe there are bushings of some sort that wear, i can't remember for sure. anyhow someone will come along, this has been talked about before if i remember correctly.

 

[rigol2000]

Yes, I was unplugging the actuator to get the noise to stop. I wasn't sure if I needed to replace that whole butterfly assembly or maybe a part thereof. I tried to search for this topic but got a bunch of crank cancer threads instead (thankfully I don't have that!).

Thanks!

 

[dantheman68]

i wonder if it has something to do with the black canister on the back of the intake, i know there is a one-way valve in there that can get messed up, but i dont know the symptoms... do you have an extra one you can try in its place... or just try disconnecting it, then shake it... if it rattles, then it is broken

 

[AREA 91]

Normal for a SHO v6.

 

[socialdeviat]

Sounds like the rubber bladder in that actuator has a leak inside. Mine doesnt sound like that...

See if it makes that sound with a vacuum pump. Or disconnect it and suck on it. Maybe its just a bad bladder inside and allowing air to pass through. But it still seems operational.

 

[dantheman68]

wow... good thing i posted in this section awhile back... now mine does the same thing, and im positive that it didnt do it before.... UGH!! its soo annoying, does anyone have the way to fix these, or want to give up one of their frontside vaccum cans so i can make it stop!!! *runs and cries*

 

[cmz829]

it also sounds like the same problem i have not sure if disconnecting the secondaries on myne would stop it never tried that but it sounds exactly like myne does i got a 95 atx

 

[dantheman68]

i found that if i move them with a screwdriver that the noise stops... are we sure its coming from the vacuum solenoid, because i just replaced it with one that i forgot i had, and nothing changed, but when i manually moved the shaft with the car running, they stopped clicking, that-is that there was still vacuum on the solenoid and the shafts were turned... im gonna try swapping the shafts tomorrow, and look more into this... its REALLY irritating, especially now i cant show anyone my newly painted intake...

 

[MD Ever]

Well it looks like I have this problem too. I was actually kinda relieved cause I thought it was something worse (cam chain tensioner, valve noise, etc.). Anyone figure out a fix for it yet?

 

[rigol2000]

Not yet. I have a set of butterflies on its way to me. I am thinking it's the assembly that has the issue. When I get a chance, I'm going to swap them out. I am assuming the new(used) set doesn't have the same problem.

 

[dantheman68]

mine are fixed... i think over time the butterfly plates come loose, i had the same noise coming and i replaced the vacuum canister and nothing changed, i also took the canister off of the butterfly plates and hooked it to vacuum and there was no noise again, i looked, and one of the plates was loose, i tightened it and then the noise went away

 

[MD Ever]

mine are fixed... i think over time the butterfly plates come loose, i had the same noise coming and i replaced the vacuum canister and nothing changed, i also took the canister off of the butterfly plates and hooked it to vacuum and there was no noise again, i looked, and one of the plates was loose, i tightened it and then the noise went away

Thanks! I'll give that a try as soon as I get a chance.