Glow plug replacement on older diesels.

Glow plug replacement on older diesels.

Glow plugs can seize in the cylinder head. If one breaks during removal, specialist extraction may be possible in situ; in other cases the cylinder head has to come off. A small replacement part can therefore lead to a much larger labour bill.

Before authorising replacement, discuss the risk of breakage and the options if a plug cannot be removed normally. Age and service history matter, and the condition of the plugs cannot always be established before removal.