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Diverter valve possibly whistling?

sun27

New member
So I think my diverter valve is making a whistling noise, only under boost. Not 100% sure is the DV, but it certainly seems to be the cause. It only makes the whistle under load above 3k rpm, roughly about the time the diverter valve vents excess boost. It literally sounds like a coach's whistle. Also I had a random epc light the other day followed by no boost. I cycled the ignition off and back on and the light was gone and everything normal again (except for whistle). I scanned for codes but none were stored. The whistle just started 100 miles ago, definitely wasn't there before. Really hoping its not turbo, but hey, JB4 for life, warranty intact. If its just the diverter valve I'll spare myself the trouble and fix it myself. I tried searching the interwebz but couldn't find anything regarding this platform, only that the diverter valves are solid now. Anyone experienced this?
 

zef

Drag Racing Champion
I am curious what you tried searching because this issue is asked very frequently, but yes, it's the diaphragm inside the diverter valve that tore or is otherwise damaged. The GFB DV+ was the go-to, but when turbosmart released their 'kompact' plumb-back DV I would say that's the preferable one. The GFB requires occasional maintenance (lubing of the piston), will throw soft codes, and piggybacks off of the factory DV.
 

zef

Drag Racing Champion
Also - check the diaphragm on your PCV. If that tears it could produce a whistling sound as well.
 

Thumper

Autocross Champion
I am curious what you tried searching because this issue is asked very frequently, but yes, it's the diaphragm inside the diverter valve that tore or is otherwise damaged. The GFB DV+ was the go-to, but when turbosmart released their 'kompact' plumb-back DV I would say that's the preferable one. The GFB requires occasional maintenance (lubing of the piston), will throw soft codes, and piggybacks off of the factory DV.

It could also just be the intake because I have been chasing the DV pony a while and still whistle down the road like an old cowboy. LOL

Also, FYI, the TurboSmart throws soft codes for voltage signal, no CEL, but it stores a code error for implausible signal.
 
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