Where are the glow plugs? Very basic question but Im trying to learn and no one I know seems willing to help. Are they under the four large plugs on top of the engine block?

 

The GH Diesel in my market was a 2.2 diesel & different to your picture.

However, in the GG/GY we had the 2.0 MZR-CD ( RF Turbo)

The plugs across the top of the engine are for the Fuel injectors.

Glow plugs (#7 RH picture) appear to be located, down between the Intake manifold & cylinder head. Probably below the fuel pipes. There is a common cable or rod connecting all the glow plugs.

 

I have finally managed to look at the diagrams and with help I think I have found the glow plugs. I will have a brief go to see if they come loose or not.