So the rattle started when I switched over from the oem muffler to the capristo...probably coincidence or not, not sure. My options were replace valve or try all the tricks others attempted. I decided to change the valve.....but before doing so, i took one last look and decided to "slightly" pinch/tap with a thin chisel on the bushings that hold the butterfly from each end so the free play is removed ....and voila....what do you know......rattle stopped ! The butterfly still moves freely, but i guess that is all it needed to remove the extra play. 500 miles and I am still rattle free.....bypass opens and closes perfectly. So if you are ready to make the 1k investment...worth on last try. Carefull if you are not intimate with this system since the butterfly could stuck and would lead to other major problems........read threads etc....
Makes sense....and good "repair". I wonder how many people have taken their 355 to a Ferrari dealer and paid $1000+ to have this repair done to the bypass valve....more than a few I bet
FoD replaced mine when it was rattling on their dime before I took delivery (pretty cool actually) but will keep this in mind should the new one eventually start - great post/tip - THANKS!
I used a dab of JB weld to do the same thing. But I pulled it and replaced it with a Cappy shortly after and have no idea how long the fix would last...
I just fixed mine with a different method of lengthening the actuator rod. Seems to have worked for the last 100 miles. I found the fix on this forum.
Hi, try shortening the rod, as in opening the valve a touch. To do either you have to take valve out as otherwise you will tear the bellows apart don't just twist the rod.
Yes, I have read that people do both - but it seems to make sense to have the rod slightly pulling the lever to pre-load the valve. I am going to try it on mine asap - after going back to stock from a Tubi and un-wiring my bypass, it (of course) rattles...
Have had the rattling valve problem for a while. Finally bit the bullet to fix it. Turns out that the main shaft was loose in the bearing. Capristo valve is ordered. Will post my experience once it's up and running. Couldn't find any solid info about it here on fchat, but looked good in the pictures and no more expensive than the f-part, so we shall see how it goes....
A visual aid would be nice. I took the preload as high as I could on mine and it still rattles. So, where the rod that the butterfly mounts to goes into the side bushing area you took out the play with a chisel?
It's probably worth me saying here that my 355 has a Porsche 911 (997) bypass valve on it - it cost the previous owner (tispkj on here and elsewhere) a tenth of the price of the Ferrari part and fits with just a small modification to shorten the actuator rod.
