Cat 308 Next gen glow plugs

[Canadian_digger]

Any one here have a 308 next gen? I’m thinking my glow plugs do not work.

My glow plug light never come on no matter what temp it is outside. I know the light works because it turns on for a slip second when your first turn the key on.

Sometimes is has a hard time starting and cranks a lot before it fires up.

In the manual it says to wait 10 seconds before starting when it’s cold.

Is anyone able to let me know if the light come on for 10 second before starting in the cold. I would appreciate it. Thanks.

 

[92U 3406]

I'm not overly familiar with the Cat Next Gen excavators but I do believe the 308 uses the same engine (C3.3B) as the skid steers. I do know Cat had a software update for the skid steers a while back that was specific to the glow plug strategy during cold starts.

Maybe someone with SIS can pull it up and see if it applies to your machine as well.

 

[Canadian_digger]

I'm not overly familiar with the Cat Next Gen excavators but I do believe the 308 uses the same engine (C3.3B) as the skid steers. I do know Cat had a software update for the skid steers a while back that was specific to the glow plug strategy during cold starts.

Maybe someone with SIS can pull it up and see if it applies to your machine as well.

This is great info. Should I get the serial number?

 

[92U 3406]

Definitely post the s/n. The folks with SIS will need it.

 

[Canadian_digger]

 

[Canadian_digger]

Cat00308EGG802762

 

[Nige]

According to the SysOp the Glow Plug light should come on when you move the key from the OFF to the RUN position. When it goes out the key switch should be turned further to the START position.

The glow plugs are powered by a relay that is pulled in by a voltage coming from the engine ECM. Maybe that relay might be the first thing to look at after checking fuses, etc.?
The other thing that springs to mind is the possibility that the glow plugs are a parameter in the Engine ECM Configuration Screen that can be Activated or Deactivated, but to check that would require ET.

 

[Rihpper]

I have a 309 next gen which has the same engine as your 308. My glow plug light doesn’t stay on either, but i haven’t used it in super cold temps. It always starts easy though.

 

[Nige]

Having looked at the electrical schematic the machine has an ambient temperature sensor. I would imagine the input from that sensor could be what activates the glow plug logic for a cold temperature start but I have no proof of that.
EDIT: There's also a coolant temperature sensor which makes more sense as a glow plug trigger. If the coolant temperature is low enough - glow plugs. If the engine is at all warm - no glow plugs

 

[Birken Vogt]

If it is your own machine, why not just put on a fixed timer that works under all conditions?

Cold = wait full time.

Warm = ignore timer and crank it up.