What’s in a VNT/VGT Turbo

Seen here is a VNT/VGT Turbo. Whatever the name, VNT or VGT same thing.

Variable Nozzle Turbo

Variable Geometry Turbo

This technology of Turbo varies its performance by directing the exhaust gases more or less onto the turbo impellor.

At low engine RPM and low exhaust gas pressure, the vanes will be adjusted to direct exhaust gases under more pressure and onto the tips of the exhaust impellor to quickly spin it up.

As engine RPM and exhaust gases increase, the vanes are adjusted to control the exhaust gas pressure driving the turbo and hold boost pressure at its set limit.

With a faulty control mechanism this turbo was lucky to provide enough boost to move off from a standing start.

With lots of moving parts inside you can see how the vanes might eventually get sticky and play up. This may also lead to damage of the turbo control mechanism - stepper ccntrol motor.

How do you look after your Diesel engines Turbo?

• - Change the engine oil regularly. 10,000km or earlier.
• - Fit a proper catch can System to reduce oil fumes being burnt and shooting up sensitive areas like the VNT/VGT vanes.
• - Get your Turbo Diesels boost pressure checked every now and then.

Common symptoms:-

• - Low Power
• - Lethargic response
• - A raft of engine faults that could easily lead to misdiagnosis.

Love your Diesel.

Look after your Diesel.

It will look after you.