I just bought this car in December, so I’m fairly new to the whole Evo scene. Been driving this car thinking this sounded correct, till one of my friends who owns a GSR asked about my BOV and I was confused. He then asked what noise does it make, I told him stututu. He said it’s not supposed to make that noise. I’ve been trying to do some research on how to fix it, or is this supposed to sound this way.

 

Sounds like you may be experiencing bov flutter. Are you using the factory bov? When does it occur?

Certain aftermarket bovs are more susceptible than others. I was getting a significant amount of flutter going up hills under partial load. I switched from a Cobb -> Tial and 90% of it went away.

 

Looks like it’s the stock bov and it is crushed. The flutter happens around 4-5th gear then another small one about 5th-6th gear.