Deep rumble at low speed

I noticed while driving my new-to-me 355 GTB at low speeds with the window down a low and deep rumble that I thought was distant thunder. I took my first real drive on a day where there were storm clouds in the distance. Then, on subsequent sunny days, I noticed it again.

Has anyone noticed this? Is it just the engine sucking air?

 

Without a sound clip its a little hard to comment....however could be anything from a non stock exhaust to a leaking exhaust flange to a failed header.

 

Can you post a sound clip?

 

I'll try to record it. It is very faint, as I say like distant thunder, and can only be discerned while the car is a near idle.

 

If its what i think it is, thats normal and one of the best sounds these cars make.

When i was a kid, our neighbor had a large stable of ferraris and when we heard that "thunder", we ran to the window to watch

I assume its off throttle, sub 2500rpm, like when cruising around a neighbor hood at 25mph? thats when mine does it

 

I spent a few minutes on youtube trying to find a vid, most only shower WOT sounds, but here is the closest thing i found to the sound, at 0:05 in this vid: https://www.youtube.com/watch?v=iIyW5RZ-S2E&feature=iv&src_vid=wmP6UdQX8qo&annotation_id=annotation_462746

 

I love the low RPM range rumble!

 

Possibly a wheel bearing.

 

There is an "air delivery tube" on each side of the engine that sometimes develops a hole that causes like air sucking hissing type of sound, its part # 164300 LH or 164299 RH.
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I recorded this while driving slowly in first. You can sort of hear the rumble at 10 and 20 seconds as the revs come off. Hard to hear though.
View attachment clip.mp3

 

that sounds normal to me.

I think you are referring to that bubbly sound as you put in clutch and come off the throttle.

it's just the exhaust.

 

Do you have a stock exhaust or aftermarket ?

 

Stock exhaust.

 

Based on the limited information given by the OP, it sounds as though they're talking about a low engine rpm - lift off/partial throttle rumble from the exhaust.

My 348 does this, which was of some concern to Me initially until I saw this clip of Jeremy Clarkson in a 348 spider from quite a few years back: https://www.youtube.com/watch?v=jUm0be3reAg (@3:40)

 

This is the way a Ferrari mechanic from the dealership explain it to me. He said yes what you're hearing is actually thunder. ... It's hot air and cold air mixing together. If we are talking about the same sound, take your foot completely off the pedal as soon as you hear the sound and you will notice it goes away immediately