Glow sensor and engine component combination

A glow sensor (10, 74, 78, 90) provides functions of both a diesel engine glow plug for aiding fuel ignition during starting and low temperature operation and an ion sensor for sensing engine combustion initiation and characteristics. Compact glow sensor components may be assembled directly in combination with an engine combustion chamber defining component, such as a cylinder head, to provide a combination in which separate housings or shells for the glow sensors are not needed. Thus, the glow sensor elements (32, 76, 80, 91) and insulation may be made larger to provide greater electrical resistance in the ion sensor electrical circuit and enhance the operation of the ion sensor function. Various forms of glow sensors may optionally be used in such a combination including, for example, metal sheath (48) type glow sensors with either isolated or non-isolated coils and ceramic rod (82) or flat plate (92) type glow sensors. Exemplary embodiments of glow sensor components mounted in a cylinder head are disclosed.