After you have drained the radiator, how do you get the remaining coolant out of the block? The engine is a 97 5.8L. I'd like to get all the old coolant and radiator cleaner out of the cooling system before I refill it with anti-freeze and distilled water. Are there drain plugs in the lower part of the block somewhere? Thanks.

 

There may be drain plugs there but I'm not familiar with your engine. The way I remove all old coolant and any flush additive without pulling plugs is to flush the cooling system a few times with clean water. I like to remove the lower radiator hose to drain the system quickly; I repeat the flush 3 or 4X. Yeah, probably more than needed by I like to make sure it's all out of there.

 

There are 2 engine drain plugs on my '96 E-150 with the 5.8L V8. I bet it's the same as your '97. The one on the passenger side is behind the starter (per my Haynes manual). I've never been able to find that one, let alone get a wrench on it.

On the driver's side, the drain plug is toward the rear of the block near the exhaust pipe. It's a tight squeeze, but you can get at it from underneath the vehicle. It's a 9mm set screw. I replaced the set screw with a conventional bolt to make it easier to remove with a wrench or socket. You can also access it very easily from the passenger compartment by removing the center consol. I do that because I also have access to the coolant lines that go to the rear heater. They are mounted way above the engine near the top of the fire wall. I disconnect the rubber hose and hold a garden hose up against the rear line until water circulates all the way thru and comes out the engine block and water pump radiator hose. Yeah, I know it's not distilled water, but it totally flushes the rear heater. I reconnect everything and then do exactly what CowboyBilly9Mile does with distilled water.

It's a lot of work, but virtually all the old coolant is gone and it leaves the system more than 50% empty by the time you're ready to add new coolant.