What are the symptoms of a variable vane Turbo?
If a vehicle has a variable vane turbo, problems can arise if the vans carbon up. The symptoms of stuck vanes are lack of power, black smoke and hesitation on acceleration. Also make sure that all the vacuum pipes and sensors that operate the turbo are operating correctly.
What happens if the vanes are stuck at open position?
If the vanes are stuck at open position as in Fig. 3, the turbocharger will fail to provide the needed boost (underboost) at lower engine rpm, and the engine will stumble. The undesirable effects of overboost and underboost are prevented by the sophisticated closed-loop control of the ECU (Fig. 4).
Why are the vanes closed on a diesel engine?
The partially closed vanes create narrow paths for the exhaust gases to pass through. This accelerates the rather weak exhaust gases and directs them almost squarely into the turbine blades, thus, creating enough torque to drive the pump even at low engine rpm. Fig. 3 shows the position of the vanes at high rpm.
How does a variable geometry turbocharger ( VGT ) work?
Explanation: To fully understand the above statements, we need to discuss a little bit about Variable Geometry Turbochargers (VGT). VGTs are used in engines to push just enough air into the combustion chamber to increase the engine’s power output. A VGT has two main sections: the pump and the driver (see Fig. 1).
If a vehicle has a variable vane turbo, problems can arise if the vans carbon up. The symptoms of stuck vanes are lack of power, black smoke and hesitation on acceleration. Also make sure that all the vacuum pipes and sensors that operate the turbo are operating correctly.
If the vanes are stuck at open position as in Fig. 3, the turbocharger will fail to provide the needed boost (underboost) at lower engine rpm, and the engine will stumble. The undesirable effects of overboost and underboost are prevented by the sophisticated closed-loop control of the ECU (Fig. 4).
The partially closed vanes create narrow paths for the exhaust gases to pass through. This accelerates the rather weak exhaust gases and directs them almost squarely into the turbine blades, thus, creating enough torque to drive the pump even at low engine rpm. Fig. 3 shows the position of the vanes at high rpm.
Explanation: To fully understand the above statements, we need to discuss a little bit about Variable Geometry Turbochargers (VGT). VGTs are used in engines to push just enough air into the combustion chamber to increase the engine’s power output. A VGT has two main sections: the pump and the driver (see Fig. 1).