355 start up noise

sure it was not the whine of the alt under load? having not started in a few weeks it had a look of charging to do

 

manifold blow ?? seams a common fault on 355's

 

Probably just some valve type noise ticking. Once the oil gets circulated and they get lubed the noise goes away.

 

Exhaust bypass valve?

 

It's the CATS same exact thing happened to me a few weeks ago. As soon as they cool down and contract the rattle will probably start again.

 

Sounds like valves tapping to me as well. Since the car has been sitting awhile, the oil has drained out of the lifters and needed some time to recirculate. I think you did not hear it above 1500 becuase it becomes too hard to hear with with the exhaust and intake noise. Nothing to worry about though, as long as the noise went away and the car ran well.

 

What you describe sounds like the self adjusting timing belt tensioners. When they age, depending on the exact position that the engine is when it stops turning, the belts put increased tension on them and they bleed down with time. When you restart the engine they rattle until the engine warms up a bit. If the belts were installed (tensioned) correctly no harm will be done as they cannot back up enough to allow the belt to get loose enough to cause harm. The noise is very annoying but the fix is very expensive. Motor out, new belts, new tensioners etc,etc.

 

Sounds like something exhaust-related to me. Especially since it goes away when warm, and is inaudible at low RPM. I'd look for a loose clamp, fitting or shroud.

 

I tend to agree. They can be noisy b*****ds.

 

My 95 355 has the same problem, it always happens on a cold start. Evan if I drove it in the morning I can come out 8 hours later, start it up and it has the same type of rattle. Then after about a minute the engine heats up and the rattle goes away, and it is not back until the car cools down.
It only lasts a short time, like a minute or so, then runs and sounds great. Sounds to me like there is nothing for me to worry about, just a little annoying.

 

Look at the air injection rails on the top of the exhaust manifolds. With a mirror you will likely see the tubes cracked just above the weld. Ferrari had us welding them and reinstalling the headers if they were still OK in the tube area. Can be welded with the header in place. Could be the only service campaign we ever made money on, as they paid us 4 hrs to R&R the headers.
Dave

 

Look at the connections between the cats and the muffler inlet. On my car one of the clamps cracked and rattled when cold.