- Engine:
- G3508 (S/N: 4WD1-UP; 9TG1-UP)
- G3512 (S/N: 5JD1-UP; 7NJ1-UP)
- G3516 (S/N: 4EK1-UP; 8LD1-UP)
Description of Change: The system for sensing oxygen in the exhaust for the G3500 engines has been improved. The improvements reduce the drift of the sensor and the improvements increase the life of the sensor. The former components are replaced by the new components that follow:
- Adapter ring for the oxygen sensors
- Buffers for the oxygen sensors
- Oxygen Sensors
Adapter Ring For Oxygen Sensors
A new adapter ring for the oxygen sensors has ports which provide the proper flow of exhaust gas through the body of the oxygen sensor. These ports can be cleaned. The interval between cleanings will depend on the amount of deposits that are normally seen in the engine's exhaust system. At sites that produce large amounts of deposits in the exhaust system, the required interval between cleanings of the ports will be shorter.
Provisions have been made in order to allow the installation of a filter in the ports that are for the flow of exhaust gas. The filter will help reduce the need for cleaning these ports. At sites which produce high amounts of deposits in the exhaust system, these ports can be filled with a piece of a cleaning pad that is made of stainless steel. A landfill application is an example of a site that has high amounts of deposits in the exhaust system. The stainless steel pad may be purchased locally. This filter will collect some deposits that are in the exhaust. The filter will help reduce the amount of deposits that are collected by the sensor. Changing the filter at every oil change interval should provide the desired protection of the sensor. Some applications may require more frequent replacement of the filter.
One side of the new adapter ring is marked with the word "UP". When you install the new adapter ring, be sure to position the adapter ring so that the word "UP" is facing upward. When you view the adapter ring from above the rear of the engine, the port for the oxygen sensor must be oriented to 7:30 o'clock.
Oxygen Sensors
Two new oxygen sensors are used. One new sensor is for use in applications with fuel from a pipeline and for use in applications with fuel from a wellhead. One new sensor is for use with fuel from a landfill. A new harness assembly is required to connect these new oxygen sensors to the new buffers. The oxygen sensor that is used in applications that are covered by the Canadian Standards Association (CSA) retains the same part number. This sensor already has an attached harness. The oxygen sensor that is used in applications that are covered by the CSA does not require the new harness to connect to the new buffer.
Note: The oxygen sensor is a component that is considered to have a limited life, just as a spark plug has a limited life. An oxygen sensor that is used in a landfill application has an expected life of approximately 3,000 hours. An oxygen sensor that is used in applications with fuel from a pipeline or in applications with fuel from a wellhead has an expected life of approximately 6,000 to 8,000 hours.
Buffers For The Oxygen Sensors
One new buffer is for use in applications with fuel from a pipeline and for use in applications with fuel from a wellhead. This new buffer is also used in applications that are covered by the CSA. The other new buffer is for use with fuel from a landfill. Both of these new buffers have an integral connector instead of an attached harness assembly. Formerly, only the buffer that was used in applications that were covered by the CSA had an integral connector.
Adaptable To: The table identifies the new components and the former components in the system for sensing oxygen in the exhaust.
| New Components And Former Components In The System For Sensing Oxygen In The Exhaust | |||
|---|---|---|---|
| Name Of Component | Fuel From A Pipeline or Fuel From A Wellhead |
Applications That Are Covered By The CSA | Fuel From A Landfill |
| Former Buffer | 3E-7565 | 138-6782 | 3E-7565 |
| New Buffer | 190-6470 | 190-6470 | 207-6039 |
| Former Sensor | 3E-7639 | 141-2494 | 3E-7639 |
| New Sensor | 196-5391 | 141-2494 | 202-8024 |
| Former Adapter Ring | 135-9851 | 135-9851 | 135-9851 |
| New Adapter Ring | 200-6984 | 200-6984 | 200-6984 |
| Harness | 199-7151 | N/A | 199-7151 |