The VGT turbo, engine by engine
The variable-geometry turbo (VGT, or VNT) replaces a wastegate with movable vanes that change the turbine's effective size: quick spool at low rpm, full flow at high. On a diesel the vanes live in exhaust soot - they stick, the actuator that moves them wears, and the truck loses boost or over-boosts. Most diesels here from the 6.0 onward use one (the 6.4's compound turbos are the exception, listed at the bottom); the failure is generation-specific and so is the fix.
This page groups the documented VGT failures engine by engine, with the components on record and Dave's prices where Dave's lists them. The maker of each turbo and actuator is named the way our records name it, per generation. A diesel not named on this page has no VGT failure on record.
Every row is a published record - see /disclosure/
6.0 Power Stroke
- VGT turbocharger sticking verified - common; low power / sluggish spool-up
Components on record: 6.0L Power Stroke VGT Turbocharger (reman / upgraded). Priced failures: /repair-costs/.
6.7 Power Stroke
- VGT turbocharger failure - generation dependent (ceramic-bearing GT32 vs journal-bearing GT37+) verified - occasional; gen1 (2011-2014): rising high-pitched whine/screech with engine speed, shaft play, oil consumption, blue-gray smoke, eventually wheel-to-housing contact
Components on record: BC3Z-6K682-A, LC3Z-6K682-A. Priced failures: /repair-costs/.
6.7 Cummins 2007.5-2018
- Holset VGT turbo sticking / actuator failure verified - very-common; loss of exhaust-brake function (the classic first sign - the VGT is the exhaust brake)
Components on record: 68048234AF, 68321378AA. Priced failures: /repair-costs/.
6.7 Cummins 2019+
- VGT turbo electronic actuator failure (HE300VG family) verified - common; underboost/overboost DTCs and defuel; lazy spool; soot build-up from stuck vanes
Components on record: 68444773AB, 68444771AB. Priced failures: /repair-costs/.
Duramax LB7-LMM
- VGT turbo vane carbon / actuator wear (LLY+) aggregated - occasional; boost flutter / hesitation, limping boost control
Components on record: 12639460, 19210790. Priced failures: /repair-costs/.
Duramax LML
- VGT turbo vane carbon / actuator wear (Garrett VVT) aggregated - common; underboost codes (P0299), limp mode under load, whistling/whoosh changes
Components on record: 19434580. Priced failures: /repair-costs/.
Duramax L5P
- VGT turbo electronic actuator failure (BorgWarner) verified - common; check-engine light with 'Reduced Power' from the turbo/boost side (an NHTSA complaint names a dealer turbo-actuator replacement on a 2020 Sierra 2500)
Components on record: 12723081, 12723083. Priced failures: /repair-costs/.
3.2 Power Stroke (Transit)
- Turbo / VGT faults (oil in exhaust after turbo) aggregated - occasional; oil traces in the exhaust downstream of the turbo
Components on record: BK3Z-6K682-A.
Sprinter 3.0 V6 (OM642)
- Turbo boost control: VNT actuator, leaks, limp episodes aggregated - common; reduced power / limp mode with underboost DTCs
Components on record: 642-090-12-00-83.
3.0 EcoDiesel gen3 (Ram 1500 / Wrangler / Gladiator)
- Turbo boost-control and throttle-body faults (P00AF, 'service throttle body' messages) aggregated - occasional; P00AF (VGT boost-control performance) and limp-mode events under load
Components on record: .
Engines without a VGT (3)
- 7.3 Power Stroke - a wastegate turbo, not a VGT - its failures are the pedestal and the up-pipes
- 5.9 Cummins - a wastegate HX35W - the sticking-vanes story starts with the 6.7 in 2007.5
- 6.4 Power Stroke - compound sequential turbos with wastegates - the documented failure is the bearing seals
- Every gasoline engine here runs wastegate turbos or none - the vanes-in-soot story is diesel-specific.
Prices are Dave's Auto Center retail, the same as in his store (the only seller this site links); a component without a price is a record with no live listing - the part page says what is known. The turbo maker and the generation differences live on each failure page - open it before buying anything, and mind the tier on every fact.