I have 2008 EVO MR complete stock. Recently have started hearing some flapping noise ( I dont think i noticed it before) some flapping noise. If i drive it on boost / WOT for sometime then drive slow I am able to hear it. It seems to come from hood and can be heard only at very slow speed (20-30 mph). Any suggestions?

Also I connected OBD2 diagnostic and saw that my car reaches a maximum of 18 psi. Is that normal for a stock EVO or should it go more.

I am new to turbo's and this car so learning about it everyday.

any info is helpful!

 

edit: wait so you hear the flapping noise after you're back to normal driving? (out of boost) or do you hear the flapping noise at full boost? (wastegate operation)

 

You should be hitting a bit more peak boost.

 

My buddies evo 8 was making some noises and it turned out to be the crank pulley was warped. You could actually see it wobbling around. And yeah, the bolts were tight. Sure its not coming from the belt area? Hope you figure it out!

 

I hear the flapping noise after Boost , when I am driving normal without any boost.

can the low boost an issue with boost leak??

 

My brothers wrx has some light modifications and an aftermarket recirculating BOV. His bov is actually making what I would call a "fapping noise" during boost at WOT. His bov isn't holding boost at +19 psi very well. You can see the boost taper down more than it should. Did you try a boost leak test?

 

have not yet tried boost leak test. its completely stock so i was hoping it will be fine. but if 18psi is less then that can be an issue.

 

Well if it's not really doing it during WOT maybe its not boost related. Is everything secure in your engine bay? I know on my evo it came without the top cam pulley cover and a wire was hitting it making some noise.

 

yea.. everything seems to be in place.. Its just very light fluttering noise at 10 mph or so.. Dont know if its normal or what.