I have only heard a few honda motors do it. Mine has for about 2 years, ever since I swapped it into my car. It was a B16 now it is a built Ls/vtec with the b16's head and replaced valves do to burnt ones before (another story). Even though different motor still makes loud breathing noise from intake, and it is not the normal air flowing sound. Could they all be damage to the throttlebody? All I know is it is strange a rare thing and was just hoping for some insite. With the B16 and the hard breathing sound, I managed a 14.50 before the piston rings gave way(also my fault).

thanks

 

hard breathing... huh?

 

I know what your getting at! My sohc civic does it, but my b16 del sol doesn't.