12/07/2026 8:38 am
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Hyundai Tucson 1.6T underboost occurs only after the engine rolls under load
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A 2017 Tucson sets P0299 during hard acceleration. Static smoke at very low pressure shows nothing, the wastegate actuator reaches commanded position and the turbo has no abnormal noise. Oil mist is present at the rear charge hose, and the symptom is worse in a higher gear.
Can a hose split remain closed during a gentle smoke test?
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13/07/2026 6:33 am
Yes. A reinforced hose can seal at rest and open when pressure, heat and engine movement combine. Test at the approved regulated pressure, inspect the underside while moving the powertrain only through safe supported methods, and look for a softened area or oil track. Verify clamps and intercooler end tanks at the same time.
Do not raise test pressure above the service limit to force the leak. If the air path holds at the proper pressure, then move to control-solenoid and actuator-load tests.
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14/07/2026 7:39 am
A 20 mm split on the underside of the rear hose opened when the engine side was lifted slightly. It had been hidden by a woven sleeve. The new hose held the specified pressure and boost matched command on the same acceleration run.