F430 bypass valve rattle

Stupid question...but what did the rattle sound like? I have something going on at start up but it disappears after about 30 seconds

 

I have the same problem.

Can you tell me where you got that spring. Or dimensions of it etc.

thanks

 

Very interesting! Was it really loud? I can sometimes kick it away w a flick of the gas pedal.

 

Another way to check if it's your valves making the suspect noise is to disconnect the vacuum hoses from the valves which will cause the valves to remain open. The rattling from faulty valves occurs typically when the valves are closed. Disconnecting the vacuum lines will be help isolate the noise you're hearing.. If it goes away after disconnecting then it's safe to assume your annoying noise is indeed the valves.

Great fix with the springs.. Just a little lateral tension on the valve is all it takes to solve this. Seems like its caused by normal wear on the shaft / shaft bushing in the valve assembly which creates the rattling.

 

Nice to see my idea put into practice

 

I think my F430 have the same problem.

Kindly share the dimensions of the spring please, or perhaps if anyone knows where we can order it online.

Thanks!

Dan

 

Excellent! Thanks for sharing photo and info.

Now time to find a seller.

Will share what I find here.

Dan

 

On the F355 the fix for the rattle was to remove the diaphragm (couple nuts holding it to the bracket. Then loosen the nut on the shaft and unscrew the diaphragm a couple turns. Tighten the nut and reinstall. This adds a little preload on the valve to hold it shut. It is presumed there is a loss of tension causing the valve to rattle.

One has to be careful with the adjustment, if you add too much pretension it can prevent the valve from opening.

Looking at the photos, there may be enough room to remove the circlip from the shaft, loosen the lock nut and do all this from below?
Again, only add one or two turns, whatever is required to eliminate the rattle, but avoid it stay constantly closed from too much pretension.

 

Yes.. I tried that fix also but it didn't resolve it for me. It seems like you need a little bit of lateral pressure on it to quiet them down.

 

that could be your exhaust box giving up

 

ha, that looks like an old school mechanical gas pedal return spring

 

Where i used to work, we had springs on a few things as a quick fix, but they tended to be a permanant fixture in time.

 

Do you have any more info on the springs? My exhaust valves rattle also, want to see if this can fix it.