Turbo/boost or ecm issue

[WVRigrat05]

Trucks done, runs and sounds good, but... at 1500 rpms in all tunes the turbo canes are shutting all the way and making way too much boost, if you hold it at 1500 rpms it comes and goes like its doing a vane sweep, I’m stumped.

[jpowel29]

Any drive pressure leaks? If not, the next thing to check would be the vane position sensor and actuator.

[Chevy1925]

Originally Posted by WVRigrat05

Trucks done, runs and sounds good, but... at 1500 rpms in all tunes the turbo canes are shutting all the way and making way too much boost, if you hold it at 1500 rpms it comes and goes like its doing a vane sweep, I’m stumped.

put the stock tune in it and see if it still does it. if so, hard part issue. if not, tune issue. the unison ring may have rusted up some from sitting and is now sticking a bit

[WVRigrat05]

Originally Posted by Chevy1925

put the stock tune in it and see if it still does it. if so, hard part issue. if not, tune issue. the unison ring may have rusted up some from sitting and is now sticking a bit

I’m gonna take it out and log it, if the ring is sticking what do I do? Pull the turbo?

[Chevy1925]

Originally Posted by WVRigrat05

I’m gonna take it out and log it, if the ring is sticking what do I do? Pull the turbo?

basically or keep driving it and see if it will loosen up. actuator could have a bad spot in it as well

[WVRigrat05]

Originally Posted by Chevy1925

basically or keep driving it and see if it will loosen up. actuator could have a bad spot in it as well

It squeals over 2,000 rpm under a load, don’t have a clue what that means.

[Bdsankey]

Originally Posted by WVRigrat05

It squeals over 2,000 rpm under a load, don’t have a clue what that means.

If it squeals you probably have a boost leak and need to make a leak tester.

[Chevy1925]

probably an exhaust leak. that would not help the surging issue either. look for soot around all exhaust gaskets. pulling the up pipes and looking at the gasket for any soot coming out between where its suppose to seal will tell you right away too. most of the time the leak is at the up pipe gaskets somewhere.

[JoshH]

I have found a squeal under load is typically a driver pressure leak from an up-pipe gasket.

[Bdsankey]

Originally Posted by Chevy1925

probably an exhaust leak. that would not help the surging issue either. look for soot around all exhaust gaskets. pulling the up pipes and looking at the gasket for any soot coming out between where its suppose to seal will tell you right away too. most of the time the leak is at the up pipe gaskets somewhere.

Problem with pulling the gaskets is 9/10 (in my area/experience) the bolts break off in the manifold.

[Chevy1925]

Originally Posted by Bdsankey

Problem with pulling the gaskets is 9/10 (in my area/experience) the bolts break off in the manifold.

hes already had the top end off. if they break off now, its cause they cross thread and never fully tighten so regardless, he will have a leak. hot engine, soak of penetrating oil and a wrench get them out every time for me but i dont deal with the back east rust bull shit.

[Bdsankey]

Originally Posted by Chevy1925

hes already had the top end off. if they break off now, its cause they cross thread and never fully tighten so regardless, he will have a leak. hot engine, soak of penetrating oil and a wrench get them out every time for me but i dont deal with the back east rust bull shit.

Yeah, everything here is rusted to hell. Friends 2011 LML broke 5/6 lower up-pipe bolts @ 112k miles when we were trying to change gaskets.

[WVRigrat05]

It’s definitely a boost leak close to the cab, I took it out and it got worse fast, those up pipes are an sob with the cab on, guess I’ll tear back apart. I used new gaskets and even torqued the bolts.

[Chevy1925]

Originally Posted by WVRigrat05

It’s definitely a boost leak close to the cab, I took it out and it got worse fast, those up pipes are an sob with the cab on, guess I’ll tear back apart. I used new gaskets and even torqued the bolts.

its not uncommon that the "new gaskets" didnt seal... i actually reuse the factory up-pipe gaskets if they are in good shape still

[WVRigrat05]

Passenger side up pipe and manifold was loose, I’ll not torque used rusty bolts again, good to go now. No soot anywhere until I pulled it apart and looked at the gaskets like you said James.