Hello y'all,

I own a 2008 Evo Mr , as the title states , every time when I accelerate into the highway their seems to be a whistling noise like when you let out air from a balloon. Not sure if thats normal.
I owned a evo 8 before and I know this is not normal. It almost sound like a leak not with a hissing but a whistle.
I'm guessing is the bov, it is not a stock bov , the previous owner install some no name bov on it. However it could be something else.

any advise would me much appreciated.

 

Sounds like a boost leak. Could be the bov leaking if its cheesy.

 

The car does pull, if it was a leak it wouldn't pull hard. not sure what it was. I guess I'll try a boost leak test just to be sure is not.
btw I think the bov is a ebay knock off bov. It had a soft and hard adjustment on the top.

 

It could be set too soft and leaking boost.

 

a small boost leak will 'whistle' and the turbo can overcome the boost loss through leak.


Just because it pulls strong or makes boost - does not rule out a boost leak.



Replace the BOV first (easiest to eliminate and pretty cheap too)

Then tighten all clamps. Yep. Pull the bumper cover to access the LICP clamps.

Then do a boost leak test if all clamps were tight and inspection for pin holes in hoses, etc...