355 I’m about done with this car…Capristo Bypass Exhaust Valve Issue (Videos)

That would have been removed during the clutch install so most likely connections need to be checked. Capristo warns on their website that if it doesn't get full vacuum it can rattle.

 

I wouldn’t be selling the car based on this. I know it can be trying at times but it looks like a simple fix. You have probably been working through a history of deferred maintenance issues and our fixes and repairs due to the age of the vehicle. Don’t stop now.

Keep persisting it will pay off.

 

I just drove mine 1500 mostly trouble free miles on a rally and it was probably the greatest car related experience of my life. I did not take it easy at all whatsoever.

Remember, it is a 30 year old race car for the road, but persist and you'll be rewarded with one of the all time great driving experiences available to us.

 

Yes I wasn’t talking about just this issue. I have owned a couple F355’s spanning a decade I’m well aware of how testing they can be. But the result when they are sorted is well worth it. Keep going.

 

Check the small metal tube where that vacuum line attaches. Mine failed years ago.

Check the other side of that little metal tube where the vacuum line attaches to the vacuum tank.

That tube cracks.....

Check the vacuum tank connections. The tank connectors crack. Mine failed years ago.

I bought a new tank and ran a vacuum line right to the bypass valve skipping the little metal tube.

It's the tiny little tube poking up between the numbers #34 & #37

Image Unavailable, Please Login

 

Sorry to hear your woes, i skirtted around this issue to some degree and just bought a 328 which is my dream car so i completely understand how painful the experience might be for you in constantly dealing with issues and thinking of letting it go, both of which sound pocket and heart breaking. I have also just had a Capristo valved exhuast fitted to my 328, these answers are very useful and i am sure the support here will help you find a solution to any difficulties. I can't imagine there is much left to go wrong after 18 months of repairs, talk to forum members here to possibly find someone else, fully qualified for a second opinion on where your car sits, at least it may give you a better idea of how much still needs attention and the cost involved. My 2cents.

 

I have repaired quite a few vacuum leaks in that area. Things that have failed on my car:

Stem on top of vacuum tank cracked. Fix documented here: https://www.ferrarichat.com/forum/posts/149396033/
Vacuum hose cracked where it was clamped onto the bypass valve. Fix: new length of vac hose
T-junction at solenoid became brittle and cracked. Fix: new T-junction
Crack in the aluminium tube that the bypass hose attaches to. Temp fix: bypass it with a length of new hose. Permanent fix: remove the cracked section and epoxy-putty some 4mm aluminium tube in its place.

All very cheap, easy fixes. It is what it is. 30 year old stuff that sees heat cycles and weather sometimes breaks. It sounds like you bought a car with a lot of deferred maintenance by previous owners. I hope it was cheap. They are great cars when sorted. Sounds like you're nearly there?

 

Find a new mechanic who has specialist knowledge of the 355.