Starters in Chevy Optra

The fuel filter on this vehicle is located inside the fuel tank and is an integral part of the fuel pump module assembly. As such, it's not replaceable by itself and can only be serviced by replacing the entire pump module. It's a "lifetime" filter.
However, you might be lucky. Unlike many cars you have to drop the fuel tank. This one has a panel under the back seat you can remove. You didn't specifiy your model so this is for a Optra LS, 1.8L engine.

the temp sensor is located on the right side of the engine under the intake manifold on the engine block.

A PCV valve's a 1 way valve that ensures evacuation of gases from inside a gasoline internal combustion engine's crankcase.------------------------------------------------------------------------------
super mb star

flashing is a severe condition, most cases it is from random multiple misfires, i would get it checked soon.

google firing order diagram for 2004 chevy optra

2005 Chevrolet Optra has four available engines: 1.4L (DOHC), 1.6L (L91), 1.8L (L79) and 2.0L (L34 GMDAT).

If you would like a belt routing diagram, it would be helpful if you would mention which of these engines your Optra is equipped with.

It is located on the left side of the engine(frt view) remove the rad hose then the 2 bolts holding the housing to the engine and you will find the thermostat.

Huh? Looking for the TWO starters? There is only one starter for your truck. This year has two different OPTIONS for starters. Meaning, it's EITHER one or the other. The older style, a huge one, or newer smaller style. Starter IS located on passanger side under exhaust manifold next to oil pan and above tranni cooler lines if you have auto tranni.

I dont know about having it unlocked at the dealership but whenever i disconnect the battery and reconnect, i use the code 6361 and the system is up and running again. hope this helps

Here is AutoZone's manual page showing the routing.