Rattle on start up

Very good chance it is a timing belt tensioner.

 

sounds a bit like oil starvation like when I used to start my chain driven 365 after a short storage.
But as these are belt driven - oil starvation shouldn't be as noticable.

 

If it's a tensioner, you better have it it towed to the shop yesterday.

 

you should get it checked out now. I am not sure but sounds like a timebomb.

rik

 

Not a tensioner bearing, a tensioner. They are a well designed failsafe device. If the belts/tensioners were properly adjusted at time of insatllation they are designed to prevent anything from happening in the case of a failure.

 

Could it be the bypass valve when cold?

 

Alternator bearing? It is located next to the bullkhead or bypass valve.

 

If you're unsure what it is, IMO it's best to be safe. Hopefully you have a trustworthy Ferrari mechanic who could listen to the noise and evaluate.

 

+1,000
Had the same noise. Found that the bearing attachment arm would tap against automatic adjuster creating this noise.

I have heard 3 cars do this from time to time now. Used to drive me nuts now I could care less..


Good diagnosis Brian. Thats what experience gets you......Not likely to learn that one doing a floor jack major.....
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I had a similar experience on my 348 at the beginning of last winter. It went away after I changed engine oil, perhaps it's the same for you.

 

Its a little difficult to diagnose noise with the engine out on the floor. If it were me I would be trying to avoid a witch hunt by diagnosing the noise while the car is still running. You may find something that does not require engine removal and save a pile of money and you will also avoid the possibility that you will spend all that money and not find the noise only to have it come back when the work is all done.



Diagnose....then fix.

 

Had a problem with a 348 sounded like a bearing going bad. when cold at start up usually then when things warmed up it would
pretty much go a way. One side of the engine was were the sound was coming from. left side bottom.
turned out to be an alternator belt,,,, sounded like a bad bearing.

 

To follow the diagnostic route suggested by Rifledriver:

You MIGHT be able to link the rattle to the hydraulic belt tensioner (or not) by heating the area around the tensioner before starting the engine. If you look at a diagram of the timing end of the engine you will see the tube-shaped tensioners. They are concealed by the black plastic covers. Not easy access of course to heat that area, but if you are motivated you could lead a tube from a hair drier between the bulkhead and the cover in that area. If the area is preheated and there is less noise (or none) on start up it will be because the tensioner starts to work (the piston moves out of its cylinder) when it gets warm; you mentioned that the noise decreases as the engine warms up.
Of course, if you lived in a warmer part of the world, there would be other ways to tackle this diagnosis!
If and when the engine is removed, a "tired" tensioner is easily spotted - the piston is virtually flush with the top of the tensioner body and the belt is quite slack.
A search of the forum will bring up the question of whether even "good" tensioners should be changed during a major. They are not cheap, but in my humble opinion, if the majors are done with relatively little time intervals it would be OK to change the tensioners every other service; otherwise, change them every time the engine is removed. Seems to me that they just get "sticky" with time. IMO, the other bit of excellent info previously in this thread is that when the idlers are set properly a sticking tensioner results in a fail safe mode.
Good luck!

 

I am getting a rattling sound also, 348 model, sounds like a loose muffler or some loose part but after about 3 or 4 minutes after the first start of the day the sound is gone. You can hear it go from rattle to nothing clear as day, and then any starts for the rest of that day nothing at all, only the first start of the day. I heard it could be the O2 sensors being loose but i checked both and they are tight, to me it sounds like it is coming from the left side. Any ideas?

 

Good to learn that you have sourced the noise. Same thing with mine. I presume that the engine is out and the bad tensioner has the piston vitually flush with the top of the body? So it's two new tensioners and two Hill bearings then......
You will surely be checking the water pump and the alternator bearing while you have a general look around. Check out a recent very illuminating thread on setting the gap at the bearing idler (should be set as in the WSM at 2.5mm)

 

Disconnect the alternator belt and see if it goes away. Mine did so I put new bearings in the alt and tensioner, problem solved.