Installation and Fault finding


Recommended Torque and tightening angle

Installation Cogen Sp

1. Use the correct wrench for the hex on the plug, and be careful not to damage the insulator.
2. When changing, make sure that no foreign substance falls into the combustion chamber.
3. When putting the plugs in, make sure that all cylinders are clean.
4. Make sure the plugs are vertical, then tighten them by hand until they cannot be tightened any further (A+B).
5. Then, use a spark plug wrench to tighten them accurately according to the recommended torque specifi cation (C+D).

DENSO recommends using lubricant on the thread.

Lubricant Torque Warning

Failure Analysis

An effective way of diagnosing the engine’s operating condition is to check if the spark plugs look
abnormal. If all cylinders are operating normally then the spark plug appearance is light grey, there are tanned deposits and there is a slight electrode erosion.

Failure Analysis