Originally Posted by frank-id
the fluid is sprayed into intake with the engine not turning with ignition on. When an engine is turning the glow plugs do not affect the start fluid. Poor advice.. Block heaters are merely a waste of time and money. Block heaters are very spendy to use. The heater does not circulate the warm coolant because of the thermostat and the radiator is trying to lose any heat. Best start method is to use start fluid carefully. My Cummins is lazy to start at temps lower than 40 degrees. A few squirts of start fluid saves the batteries and the starter. The number one reason for starter failure is low volts in the batteries. Frank
Frank-id, those are blanket statements. This IS engine specific.
Firstly, my bus has a T444e and the block heater works great. It is noticeable easier to start if it has been plugged in for 1-2 hours and uses about 900w when plugged in. That is hardly "spendy" and well worth doing. Why not try every safe option possible? I recently started my bus after having it sit for 7 months in -20°C (-4°F) temperature. The glow plugs work, so a plugged in block heater, a charged battery and oil added to the HPOP reservoir - that's all it needed.
Secondly, the best reason not to use starter fluid on my engine? Because the manufacturer of the engine clearly says not to! A big, red warning label is posted next to the air-intake which seriously advises against it; mentioning air-box explosions. You see, the second the key is turned to the on position, the glow plugs are heating up. They will cycle on and off until a certain engine temperature is reached (or it has a timer.. I'm not entirely sure. They stay on for a bit after the engine starts, though). This is by design. If you happen to have ether in a cylinder when the glow-plugs come up to temperature, the ether will ignite. It doesn't matter if the air-intake valves are open, or the piston is before TDC (which can blow a head gasket, damage piston rings, bend rods, etc). If the glow-plugs are working properly then there is no reason to have ether in there anyway.
My opinion? If your engine has glow-plugs then don't risk it.