From MY 2005.5, the Combo-C is also optionally available with a Z 16 YNG DOHC engine. The Z 16 YNG DOHC engine can be operated both with natural gas (Compressed Natural Gas) and petrol and is already familiar from the Zafira and Astra-G estate models. The Combo-C with Z 16 YNG DOHC engine is available in all body variants and comes exclusively with a manual transmission. Thanks to the underfloor location of the tank system, the load capacity of the Combo-C with Z 16 YNG DOHC engine is not adversely affected.
The Combo-C with Z 16 YNG DOHC engine essentially differs from the Astra-G CNG and Zafira CNG as follows:
- 3 compressed natural gas tanks located under the floor and featuring a new bracket concept
- New bottle valve
- New CNG pressure reducer
- Revised layout of CNG components in engine compartment
- Standardised screw connections for the CNG pipes throughout the entire system
- Revised exhaust system layout
Technical Data
Technical Data survey for the Combo-C CNG:
| Engine | 4-cylinder, 1.6 l |
|---|---|
| Power output | 71 kW / 97 hp |
| Maximum speed | 166 km/h |
| Fuel tank capacity | approx. 19 kg CNG, 14 litres petrol |
| Type of fuel | Natural gas/biogas or petrol |
| Fuel consumption / 100 km | ø 4.8 kg (H gas) |
| Range | Natural gas approx. 370 km; overall approx. 550 km |
| CO 2 emissions | 130 g / km (H gas) |
Bracket Concept for the Cng Tank System
The Combo-CNG has three separate pressurised gas tanks located in front of and behind the rear axle and connected with each other by stainless steel pipes. The CNG tank system used on the Combo-C CNG differs from those on the Zafira CNG and Astra-G CNG primarily in the fastening concept used.
On the Combo-C CNG the base frame for attaching the rear pressurised gas tanks is located on the mounting points for the trailer hitch frame. So that the customer is still able to fit a trailer hitch as well, the two base frames have been combined. As a result, no additional mounting holes are required.
Each of the three pressurised gas tanks is fastened to the corresponding mounting points of the base frame of the CNG tank system by means of two tension straps. The tension straps are each attached to the base frame by means of a bracket.
The installation of a CNG tank system has meant that the spare wheel has had to be dispensed with; this has been replaced with a tyre repair kit.
| 1 | Bracket for pressurised gas tank retaining strap | 3 | Struts for attaching the brackets for the pressurised gas tank retaining straps |
|---|---|---|---|
| 2 | Device for trailer hitch |
Protective Cover for the Cng Tank System
The entire CNG tank system is fitted with protective covers to protect it from damage from outside. These protective covers are fitted with warning notices (1) and should only be removed by trained specialist personnel, observing the appropriate safety regulations.
Bottle Valves of the Cng Tank System
Like the Zafira CNG and Astra-G CNG, the Combo-C with Z 16 YNG DOHC engine is also fitted with a safety valve for each of the three pressurised gas tanks. In terms of design, the valves used on the Combo-C with Z 16 YNG DOHC engine differ only slightly from those used on the Zafira CNG and Astra-G CNG. In terms of function, however, the safety valves on the Combo-C with Z 16 YNG DOHC engine are identical to those on the Zafira CNG and Astra-G CNG.
| 1 | Fuse | 4 | Connection for bottle valve outlet pipe |
|---|---|---|---|
| 2 | Non-return valve | 5 | Connection for bottle valve inlet pipe |
| 3 | Electromagnetic valve |
Bottle Valves of the Cng Tank System (Continued)
The bottle valves of the Combo-C with Z 16 YNG DOHC engine also have a device for manually shutting off each individual pressurised gas tank (2). During operation, the bottle valves are controlled by the electromagnetic valves (1). Each of the three pressurised gas tanks is fitted with its own bottle valve for this purpose.
When inspecting the CNG system, each individual bottle valve can be switched off separately, independently of the other two bottle valves, using TECH2. This facilitates more targeted and more accurate fault-finding.
For safety reasons, the bottle valve of the pressurised gas tank in front of the rear axle is also fitted with a non-return valve. This non-return valve prevents ingress of any ignited gas into the CNG tank system and does this by using the increase in pressure that arises in this situation to shut off the bottle valve. The bottle valves of the pressurised gas tanks are screwed into the pressurised gas tank and cannot be replaced during a service. Only replacement of the entire pressurised gas tank by trained specialist personnel is permitted. Every operation carried out on the CNG system must be appropriately documented in the Inspection Booklet found in the vehicle.
Cng Pressure Reducer
The Combo-C CNG has been fitted with a new CNG pressure reducer. However, the function of the CNG pressure reducer remains the same. Only the design and its location in the engine compartment, which was determined by the vehicle, have changed. The CNG pressure reducer is now located in the engine compartment on the left-hand side, viewed in the direction of travel.
Illustration L0014589 shows the new CNG pressure reducer.
Cng Pressure Reducer (Continued)
As before, the CNG pressure reducer is actuated by an electromagnetic valve (1). For diagnostics purposes, the CNG pressure reducer (2) can also be actuated with TECH2, like the bottle valves of the CNG tank system. The new pressure reducer is also connected to the engine's coolant circuit by means of two coolant hoses (3) in order to prevent the pressure reducer from icing up inside during operation.
Combo-C Cng Exhaust System
The underfloor location of the CNG tank system meant that the exhaust system had to be modified. Compared with the exhaust systems on the Combo-C, the exhaust system on the Combo-C CNG is shorter. It is not, as is usual, routed over the vehicle's rear axle. Instead, it terminates before the rear axle and is routed to the outside in front of the wheel housing of the left-hand rear wheel.
Emergency Tank
The emergency tank for the Z 16 YNG DOHC engine has a capacity of 14 l and a range of approx. 180 km. It is located in front of the rear axle, between the CNG tank modules located in front of and behind the rear axle. The structure and function of the emergency tank is identical to those used so far on the Zafira CNG and the Astra-G CNG.
Switching from Natural Gas (Compressed Natural Gas) to Petrol
Operation can be switched from natural gas (Compressed Natural Gas) to petrol by means of a switch.
Operation is switched from natural gas to petrol by means of a switch which is located in the centre console in front of the shift lever. This position was previously occupied by the switch for the driver's side seat heater.