Glow plug working life

[Dr Gary]

Does anyone have information (not speculation) on the working life of glow plugs--3.0 direct injection.
Either mine are losing performance, or the relay is dropping out too quickly.
Missing for 3 seconds, then all good. Only on cold ( well 10c) mornings, first start. Warmer days starts correctly first crank. No issues rest of the day.
I know the water temperature sensor tells the system how long to leave power on. This sensor has been in the Patrol for 12 years.

[mudski]

Depends on their use. As a daily I would say anywhere from 5-10 years. Hard to tell. Time the relay when you start it. From key on to the relay clicking. Remove the connections and give them a clean. Also all earth connections. Some people bypass the relay and put their own timer in. Jaycar sell one.

[BillsGU]

On cold mornings I just leave the ignition on for about another 10 seconds after the glow light has gone off. The glow plugs will still be heating the engine. The Patrol then starts easily.