Cranking a newer diesel

[stroker_ace]

Ok, I have been told that on the newer diesels, they no longer contain a glow plug to aid in starting the diesel engine. They are now using the ECM to control the timing of when the fuel is injected. I was also told that you just have to wait until the little icon (which looks like a spring or coil) is no longer lit up on the console. Is this true? Or can I just hop in and crank it right up which I have done on accident before and it actually cranks the truck up faster if I do it that way. It usually takes 2 or 3 seconds for my truck to actually begin running when I wait for the icon to go off. Sometimes it cranks right up though. So, do I need to wait until the icon goes away? Will it damage anything if I do not wait?

[emperorjordan]

the 6.0 powerstroke does still have glow plugs, I assure you. I have broken the connector to several of them myself

Yes you need to wait for the squiggle to go away before you start cranking. Even then, you will find the the 7.3 and 6.0 will crank longer than most diesels or gas motors before firing because we need to build enough oil pressure in the High Pressure Oil pump to fire the injectors. This is completely normal.

[stroker_ace]

That answered it. Thanks

[stroker_ace]

but... what will happen if you repeatedly do not wait for the squiggle to go away?

[emperorjordan]

it will take much longer cranking before it fires.... and then it will run rough for a bit if its cold out. It is much harder on the starter and electrical system in the truck since so much draw is required out of the FICM and starter at the same time during cranking.

[Galaxie]

The glow plug light is kind of a dummy. It actually isnt connected to the actual time the GPs run. The glow plug on time is controlled by the Powertrain Control Module (PCM) and is a function of oil temperature, barometric pressure and battery voltage. The PCM enables the GPCM that drives the individual glow plugs. Glow plug on time normally varies between 1 and 120 seconds. In addition to PCM control, the GPCM internally limits the glow plug operation to 180 seconds regardless of PCM commanded on time. So even if that light is on for 10 seconds, your GPs might only flash on when your motor is hot. In the winter, I go a good 15 seconds after the light goes out for the plugs are still on.