I have a 5.2l and recently drained the engine coolant to flush out what I believe has been the same sludge that was running through for the last 100k miles. I flushed it because I thought my heater core was going out. Now that I have nothing but clear water running in the engine, i'm concerned that I need to hurry and put coolant back in. What is the volume, in liters/pints of coolant, should I fill?

 

You will need aprox. 2 gal of antifreeze added to your system. It is better to run distilled water in your system because of mineral deposits that will occure with regular water. The only way to fully clean out all water in the block is to remove one or more of your block drain plugs and disconect the lower radiator hose. Also remember to burp the system. I don't know how hot or cold your weather is though. But this will get you good all around protection.

 

I just use the 50/50 mix so that if I'm out and about and need to add some I can just have a premix ready and waiting. (which I actually needed the other day I think I have a leaky drain plug please god no!)