Just a bit stumped with this one.
The car has had a revo stg1 map on it, previous owner had had this done, so fitted a revo CAI this weekend. Have been through the usual paranoia about all the extra noises it makes from the standard air box etc.
But after taking my mechanic mate out in it, and not telling him of my suspicions he too heard this sort of flapping/ hissing noise 3.5-4k rpm it then continues to maybe the 5k area and stops, I've checked all the CAI pipes - have been done up tight etc.
Just checked the DV, and again can't really see anything up with it (is the older diaphragm one)
the noise seems to not be there going from a high gear 6 to 4th and going past 4k.
probably totally unrelated but I've also noticed a burp/pop noise from the car standing still when revved. 0-2.5k rpm at 1.2k rpm every time.
anyone have any thoughts? Can the DV be broke from no obvious signs/ tears?