boost spike on AAZ stuck wastegate?

[rallydiesel]

rallydiesel tells me that putting a bleed valve in the line that goes to the wastegate from the cold side housing won't fix my problem because the turbo will still build up pressure on the hot side. I'm saying that's not possible. AmIrite?

Well it will fix your boost spikes but you will run high exhaust pressure and temperature because the wastegate will be closed. The turbine creates resistance and it's this resistance that the turbo uses to spin the compressor. You want the intake pressure to exhaust manifold pressure ratio to be as close to 1:1 as possible. Anyways, the best solution would be to get your wastegate functioning again.

[Thezorn]

Im pretty sure his boost spikes he is refering to is just a jammed wastegate, so he is already seeing the the higher pressure and EGTs if he is going to get them. And yes, best thing to do is get your wastegate unstuck.

well maybe I should try loosening one of the bleed line bolts and see how it affects my boost level...

Like I said In my other post, this will not help you to lower your boost. Think of it like this, exhaust gas is used to power the turbine (the wheel that is in the hot side of the turbo) this turbine is in turn connected to the compressor wheel (cold side of the turbo) and turns the compressor wheel equally as fast as it is spinning. As your engine RPMs rise, more and more exhaust gas is created, in turn flowing more volume or gas through the turbine and ultimatley increasing the speed of the compressor wheel making it pull in and compress alot more air. The function of the wastegate is the controll the amout of gas that gets to the turbine. There is a hole in the axhaust side of the turbo before the turbine, this hole routes the exhaust gas to a valve that is usually closed (or seated) Once your engine flows enough exhaust gas to get the turbine spinning fast enough and the compressor spinning fast enough to compress the intake air to 12 psi (factory settings) that small metal line that you see on the cold side of the turbo going to the wastegate, which is also charged to 12 psi, telled the wastegate to open. When this psi is reached the valve that has been closed now open, rerouting the extra exhaust gasses around the turbine and out the exhaust, limiting the speed of the turbine wheel, limiting the amount of air the compressor pulls in, and ultimatley limiting the psi to the amout it is supposed to be(12).
Hopefully this helps, so all you need to do is fix the wastegate

[ilikevwdiesel]

http://en.wikipedia.org/wiki/Turbocharger#Wastegate

[R.O.R-2.0]

my audi 5kTD did the same thing (K24) with the wastegate un-hooked.. (same thing as having it stuck basically)

except that the K24's have "magic" wastegates.. they eventually pop open from the HIGH exhaust manifold pressures, and save the turbo from killing its self.

idk, K14 wastegates may be magic too, if they function correctly..

YES, you have to take the turbo off the car to get the wastegate off usually.. its easier that way, and the risk of breaking those little bolts is greatly reduced..

[ilikevwdiesel]

replaced the turbo with a spare I had in my pile. runs at 12psi max now.

[Thezorn]

replaced the turbo with a spare I had in my pile. runs at 12psi max now.

 Good stuff!!!

[ilikevwdiesel]

replaced the turbo with a spare I had in my pile. runs at 12psi max now.

 Good stuff!!!

thanks freddie you the man.