The 2.8-liter V6 turbo engine Opel Z28NET was produced in Australia from 2005 to 2008 and was installed on the Opel Vectra and Signum until it gave way to the similar Euro 5 unit A28NET. The same engine was installed on Saab cars under its own B284L index.
The Z family also includes engines: Z20LET, Z22SE, Z22YH, Z24SED and Z32SE.
In the early 2000s, GM needed a powerful engine for its European models and, according to the already established tradition, the development was entrusted to the Australian division of Holden. By design, this is a classic V6 engine with an aluminum block and cast-iron sleeves, a pair of cylinder heads with four valves per cylinder, a timing chain and intake phase shifters. Fuel injection is distributed here, and Mitsubishi TD04 Twin-Scroll turbine is responsible for supercharging. Since hydraulic compensators are provided here, it is not necessary to adjust the valve clearance.
In addition to the usual version of the Z28NET with 250 hp, there was both a more powerful Z28NEH with 280 hp, and a Z28NEL derated to 230 hp and 330 Nm without a phase control system.
The engine was installed on:
- Opel Signum A (Z03) in 2005 – 2008;
- Opel Vectra C (Z02) in 2005 – 2008.
Specifications
| Production years | 2005-2008 |
| Displacement, cc | 2792 |
| Fuel system | distributed injection |
| Power output, hp | 250 |
| Torque output, Nm | 350 |
| Cylinder block | aluminum V6 |
| Block head | aluminum 24v |
| Cylinder bore, mm | 89 |
| Piston stroke, mm | 74.8 |
| Compression ratio | 9.5 |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | yes |
| Turbocharging | yes |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 6.0 |
| Fuel type | petrol |
| Euro standards | EURO 4 |
| Fuel consumption, L/100 km (for Opel Vectra 2007) — city — highway — combined |
17.1 7.3 10.9 |
| Engine lifespan, km | ~300 000 |
| Weight, kg | 215 |
Disadvantages of the Z28NET engine
- In the timing drive, three Morse leaf chains with a modest resource are used here, often they are extended even up to 100,000 km, and their replacement is difficult and very expensive.
- This unit overheats quickly, so keep an eye on the condition of the cooling system, besides, the thermostat here is not very reliable and antifreeze leaks quite often.
- The thin-walled air duct that goes from the air filter to the intake manifold is quickly frayed. From unaccounted for air, the engine starts to work unstably.
- The turbine itself is reliable and only the wastegate membrane and bypass cause problems. Their failure turns into insufficient or excessive boost pressure.
- The weak points of this motor also include an electronic engine control unit, a gasoline pump, an oil pressure sensor, a power steering pump and an electric vacuum brake booster.
