hi guys .

i drive a 00 si that i just bought, and when i start the engine there is a weird noise that comes up until the car is warmed up .. it kind of sounds like its grinding, but not really .. is this normal ? if not, what could the noise be, and how can i fix it ? the car was modded with a fuel regulater, short ram intake, dc headers, high flow cat and an evo 2 exhaust, could it be because of one of them ?

also, when i shift gears, theres a sound that almost sounds like a blow off valve, only the car isnt turbocharged .. can any one help me with what that is ?

thanks for ur time and help ..

 

that BOV sound is probably your cold air intake, you can hear the hiss from the engine sucking air passed your throttle body $.02

 

Free bump for wanting to know about the same thing.