Damage patterns on lambda sensors

Due to their installation position, lambda sensor are subjected to high temperatures, aggressive chemicals and vibrations. Therefore, they are subject to wear and ageing. We recommend having the function checked every 30,000 km and/or on every exhaust emission check.

Possible malfunctions may be perceptible if the engine is running rough or fuel consumption increases. The workshop professional can determine definitively whether the lambda sensor is functioning properly. A visual inspection alone is not enough.

A bent sensor leads to a faulty signal transmission.
A bent sensor leads to a faulty signal transmission

Bent sensor

The sensor was probably installed incorrectly and the signal transfer can be disrupted as a result. The sensor should be replaced.

A melted cable or a melted plug indicates unintended contact with the exhaust system.
This damage pattern indicates unintended contact with the exhaust system

Cable or plug melted

These damages result from contact with the exhaust system. The sensor must be replaced.

The protective tube shows heavy carbon deposits which can lead to malfunctioning of the lambda sensor.
Carbon deposits lead to malfunctioning of the lambda sensor

Carbon deposits

The protective tube exhibits heavy carbon deposits. This can arise from a mixture which is too rich, wear on the engine and valves or leakage in the exhaust system. Since the carbon deposits block the openings in the protective tube, the sensor can no longer work properly.

Water in the adapter leads to corrosion of the contacts.
Water in the adapter leads to corrosion of the contacts

Rusty contacts

In this case emerging water has penetrated and causes the corrosion of the contacts. On replacement of the sensor, the seating of the plug as well as all connections between the sensor and engine control unit must be closely inspected.

Frayed cable indicates a heavy pulling effect.
Frayed cable indicates a heavy pulling effect

Frayed/broken cables

The sensor was probably subjected to a heavy pulling effect. On replacement, ensure that the cable not routed too tightly.

Defective seals lead to the penetration of water.
Defective seals lead to the penetration of water

Cable seal loosened

The sensor was probably routed too tightly. Water can penetrate. The sensor should be replaced.

Heavy white or grey deposits indicate that fuel additives are used or the engine is burning oil.
Heavy white or grey deposits indicate that fuel additives are used or the engine is burning oil

White/grey deposits

Heavy white or grey deposits indicate that fuel additives are used or oil is being burnt. After remedy of the cause, the sensor must be replaced.

Heavy white or grey deposits indicate that fuel additives are used or the engine is burning oil

Heavy white or grey deposits indicate that fuel additives are used or the engine is burning oil