not building boost, am i missing something? Options

[easternpiro1]

Hi all, was wondering if i can get some feedback on something i was missing. here's the story:

recently a friend and I fixed a leak due to stripped thread in the head causing a leak between the exhaust manifold and block.

after rethreading and putting everything back togehter leak is gone BUT now im seeing much lower boost numbers after taking it for a drive.

I own an AEM tru boost controler/gauge and the boost is currently set to stock wastegate pressure (8psi) and consistently held this pressure PRIOR to fixing the exhaust leak.

as of today, my first drive out, my car would not pull past 5psi and touched 6psi BRIEFLY. I double checked my IC piping and adjusted and retightened.

when i went back out the car would only boost up to 4-5 psi adn sometimes as low as 2-3 max.



Im pretty sure its a leak somewhere but it can only be one place as the only IC piping that was removed was the piping coming from the turbo (charge side) i have checked and double checked it.

is there something im missing? any helpful hints would be appreciated! thanks!

[easternpiro1]

Matt...

1. Out of all the 3sgte owners over all the years, none of them had ever had a bad wastegate actuator that needed to be replaced.
2. when a turbo "goes bad" it either produces ZERO boost (because the exhaust fins are missing) or it produces boost like normal but spits out lots of blue smoke from oil burning.

A bad turbo or a bad wastegate is not your problem.

Im hoping its not either w/g or turbo, I took out my w/g and a friend of mine tested it using a hand held pump with a vaccum meter on it, and neither of my old w/g would hold vaccum. Additionally, I can pull the wastegate rod by hand, which was previously difficult to do.

Can you take a general picture of your engine bay, intercooler piping, and a close up of the turbo/downpipe/manifold area?

How are you measuring boost? What brand of boost gauge are you using and where is it connected to?

WEIRD o.O im still not satisfied with the consistency of the boost (will only hit 6.5psi instead of high7's) which means the w/g is still open partially but im glad i know exactly what it is, however not the question is how to go about unsticking it (as was stated above)

NO IT DOES NOT!
The difference between 6.5 or 7.5 or whatever is due to the accuracy of the boost gauge, and also the elevation of where you live and the weather temperature outside. Just because the wastegate is said to be set to 7psi from the factory, doesn't mean that you will get EXACTLY 7.0psi.

I will definately take pics of the engine bay ic piping etc. I am measuring boost by way of AEM tru boost. The Tru boost is not controlling anything at the moment, and is only connected to read PSI.
As far as the inaccurate reading I appreciate you clearing that part up for me! I was going by a number that was quite consistent from a certain period of time to it not being consistent at all, however it wont get that high anymore.

Put the stock wastegate back on.
Remove the boost controller and just connect the port from the turbo to the port on the wastegate together with some good quality 4mm fuel line hose. Then take the car for a ride an see if you can make anywhere from 5-8psi of boost. If you can, everything is working correctly and you need to then install your boost controller and set it up for more boost.

took the car out for a drive and it held to 3lbs then eventually dropped, and would not build boost at all eventually

Because you put some crazy aftermarket wastegate actuator on that was never meant to be used with this turbo and your flapper door is probably blowing open every time you boost.

The boost controller was not hooked to the turbo or wastegate until i broke the motor in I have always used the 4mm fuel line hose going from the turbo to the port on the wastegate, i have never messed with it or anything The car behaves in the exact same way as when I put the new wastegate on. boost goes to zero (no smoke, and all fins are intact on the turbo)

I DO hear a loud whirring noise when under load as if the car is spooling, I dont think it is a leak because Ive used the boost leak tester for the system and heard nothing.

I'll take some pics tonight. I really appreciate all the help!

This post has been edited by easternpiro1: Jun 6, 2012 - 2:48 PM