16g dying wastegate

[idt512]

I bought an Evo3 16G a few months ago that was lazy on building boost. I shimmed the wastegate with 3 washers for a total of about .190" inch, and everything has been good since, well 4 months later and I notice the turbo losing peak boost, and then a few days later it was lazy to build boost all over again. So i inspected the wastegate and found that i could move it 1/8" by hand again. Added 2 more shims to about .250 and all is well again... But im curious if wastegates fail this way? Or is something causing my wastegate to lose tension?

 

[Dsmkauai]

Upgrade to a holset actuator bro! Be done with loosing boost haha. The wg just can't handle the psi your trying to push and blows open easy. Also have you done a boost leak test or inspected turbo for shaft play?

 

[JusMX141]

At this point the flapper's barely opening at all with 1/4" of shim between the actuator and the mounting towers. Full arm travel is only about 3/8" on a new 16G actuator.

Something's either wrong with the actuator or the turbo, or you have a massive boost leak somewhere. Try replacing the actuator altogether with a new one or a known-working unit to see if it fixes your problem.

 

[idt512]

I've checked for boost leak and verified it as well by watching my AFRs and look look right on target still. No pre-turbo exh leak. Car runs & drives perfectly fine in normal driving. My other thought was a clogged aftermarket catalytic. But the fact that the wastegate arm had play all over again tells me it's the wastegate.