[Tom]

Originally Posted by pjmoreland

It allows a small amount of coolant to circulate when the engine is cold and the thermostat hasn't opened yet. From what I've read, having no coolant circulation during warm-up can cause temperature spikes in the heads. As an alternative, coolant can circulate through the heater core during warm-up, but this doesn't work if you've got A/C with a shutoff valve to the heater core. Most people end up adding a small hose from the front of the intake manifold to the top of the water pump. I thought it would be cleaner to just drill the missing hole instead of adding this extra hose on the front of the engine. Another solution is to drill some holes in the thermostat.

Cool, thanks