How to Fix Glow Plugs

Glow plugs are the diesel equivalent to spark plugs for gas-powered engines. Unlike spark plugs, glow plugs do not generate an electrical spark. Instead, they heat up slowly until they glow, hence the name. Glow plugs are especially useful for starting diesel engines when they are cold. Typically, when a glow plug goes bad, it should merely be repaired. However, a dirty or corroded glow plug can make it difficult to start the engine. If a glow plug is simply dirty, it can be fixed by cleaning.

Instructions

1

Remove the negative battery cable on the diesel engine with a socket set.

2

Pull the glow plug wire from the top of the plug by hand.

3

Slip the plug wrench over the glow plug and turn it to the left to twist it out.

4

Scrub down the bottom of the plug with a wire brush. Use the same brush to clean off the socket the glow plug was screwed into. Use a towel to wipe off both the plug and the area around the plug socket on the diesel engine.

5

Screw the glow plug back in by hand, then tighten it with the plug wrench. Replace the glow plug wire.

6

Replace the negative battery cable with the socket set.