I disconnected my actuator just to run it to see what it would do for a couple miles. (just pulled the air line off of it). got on it and droped the go pedal and it still blew off. That wonderfull sneeze . But then I thought to myself.. *** is is still blowing off for if I disconnected it? has anyone ever done this before? Can anyone explain what is happening? didnt make a difference in boost ( getting 25) and acts the same.... was my actuator ever working and how can i tell if it works or not. .. i got a edge cs in it and have noticed at idle that it says that my wasgate is open at idle, and as soon as i hit the gas just a little it closes. but thats just a guage. i went under the hood and put my hand on it and looked at it, had my friend fire it up . no movement, and then touch the gas and didnt move at all. but gauge says it went from 0% to 99% closed ????? no clue whats going on.
i understand that there is pressure that will push it open to get that sneeze sound from the blow off. the sound is EXACTLY the same as if the actuator was connect. need some help

 

Your wastegate can NOT open at idle. It is NOT posaable.

The only way the wastegate can open is if boost overcomes the spring, or boost bled into the canister to overcome the spring.

FYI...

You will NEVER hear the factory wastegate on a 7.3. NEVER.

You may be having issues with the EBPV (Exhaust Back Pressure Valve)

 

BTW, welcome to the site!!!

 

took back pressure valve out, so what is the ccchhheewww sound when i drop the pedal?
why would guage read that it is 99.8 % closed when in netrual with a feather on the pedal. shouldnt i see that the actuator move even a hair?

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and thanks for the welcome

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is the wastegate N/O or N/C?

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wow im stupid , scratch the last question

 

i believe the sound is compressor stall.

 

I'm no turbo expert. Teach me Joe. When I let off the throttle and hear blow off, isnt that the wastegate? I thought it was.

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Turbo stall occurs when the demand for air pressure suddenly drops, such as WOT to suddenly no throttle, or on harsh shifts at high power levels.

Turbo flutter is caused by (What I can only speculated) as turbulence in the turbo. It generally happens through-out the RPM and boost band. You will know it when you hear it.

Turbo stall sounds like flutter, but only for a millisecond as the compressor wheel stalls.

Here is stall on my truck.

 

What your hearing when you let off the throttle is boost pressures popping back out the intake.

The ONLY way for the wastegate to open is by overcoming the spring pressure against it... When you let off the throttle there is no pressure against the spring, hence the wastegate will not open.

Not to mention the way the factory wastegate is made there is no way you could hear it.

 

when geting on the highway my truck bluids up boost fine but then blow off the pressure but i it thought it was normal at first with the wastgate but you said you cant hear the wastgate. it seems to falls on it face after. does that sound like the Exhaust Back Pressure Valve failing. what is the wastgate spring pressure rate

 

Sounds like a boost leak... blown boot, hole in an IC pipe...

 

Sounds to me like normal 4R100 operation. When getting on the freeway it generally will shift and the RPMs get into that range where EGTs go up and of feels lacking on power.

Once you get up to speed its fine though. Always been like this for me.


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