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Old 09-24-2012, 07:07 PM   #39
Scooby Specialist
Member#: 183480
Join Date: Jun 2008
Chapter/Region: South East
Location: Valdosta, GA
2011 Audi Q7 S-Line
2001 Subaru Forester


Originally Posted by OC_Nooby View Post
OK boys, I don't know what to make out of it....

I unhooked my boost source to the wastegate. One would assume that once you unhook this you should get a crap ton of boost. Well guess what, it pegs at 22psi ahahhahah. So then I decided to wire the flap shut (maybe the back pressure was opening the wastegate), nope still 22psi.

I unhooked it and left the flap open for ****s and giggles, 2-4psi max.

Now I'm thinking the the wastegate flap is not sealing. This makes sense as I'm always boosting a lot later and can't surpass 22psi.

Has anyone seen this before. I'm just that lucky? FML.

i already posted a couple weeks ago telling you that i have seen this exact issue before, and that based on your troubleshooting and descriptions, it sounded like it was the wastegate not sealing all the way. i quoted/highlighted it below for reference.

Originally Posted by amalgrover View Post
the few times i have seen the issue you are describing it has been one of two things...

the wastegate stuck open, and actuating it by hand fixed it


the boost controller was messed up, was replaced, and was good to go

...since you said you have tried 2 different boost controllers, i would think the problem is not in the boost controller. so either something is wrong with the wastegate, or you have a decent sized boost leak. remember, a boost leak is going to automatically be a vacuum leak at idle, and while sometimes the leaks will not show up until the motor is in boost, alot of times they are present 100% of the time. this means that you could take a can of carb cleaner, and with the engine running spray around the vacuum lines, intake manifold, intercooler, etc. and see if the idle changes. if it changes when you spray somewhere, you found your leak. this doesn't always work, but it does work alot of the time.

you are going to need to either:

a. actuate the wastegate flapper by hand by grabbing the arm and forcing it open and closed to see if you can get it to fully close like i said to do in the highlighted post above


b. remove your downpipe to further inspect the wastegate
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