Damage patterns on pin-type glow plugs
As with spark plugs, there are characteristic damage patterns for glow plugs that make it possible to determine the cause of the damage. For example, melted or blown-up glow pencils can often be observed in defective pin-type glow plugs.
Overheating damage can be caused by the following:
- incorrect injection point or injection pattern.
Check: injection point
- the incorrect amount of fuel is injected.
Check: fuel flow rate
- combustion error due to oil in combustion chamber.
Check: leaks in valves and pistons
Overvoltage damage can result from…
- installation of the incorrect glow plug (12V instead of 24V).
Check: was the right glow plug selected?
- defective control unit, which generates excess voltage or shuts off the current too late. Check: control unit/glow relay
- a generator that generates too much voltage.
Check: generator
A broken heating coil is the result of…
- extreme overheating or overvoltage.
Causes: see overvoltage damage
A broken glow pencil is an indication of…
- an incorrect injection point, an incorrect injection pattern or a faulty flow rate. Check: injection point, fuel flow rate.
Breakage on the housing or connector results from…
- tightening to the wrong torque
- incorrect application of the wrench.
