Radiator flush/fill 4.6L

Corey A Pyles · Jan 9, 2019

Did I flush/fill my radiator properly? I drained it, ran a couple gallons of distilled with cleaner for a couple minutes, drained it and poured a couple of gallons with the plug open, closed it put in 1g of pure antifreeze and 3/4g distilled water. I pulled off the upper radiator hose and poured water in that until it came out of the thermostat mount. Now I'm letting it sit, not sure what else I should do, I know that there is air in the upper radiator hose but not a lot of it. I don't have a coolant crossover so I'm hoping that pulling the hose did the same thing. *edit: It's sitting on jack stands nose down in the driveway

edit again: While running the engine with the cleaner I made sure it was producing heat and when I shut it off to drain the flush the water was warm. It never left the jack stands during this process.

07GtS197 · Jan 9, 2019

You didnt back flush the entire cooling system or block so theres still old coolant in there. If you want to you can pull the upper and lower radiator hoses, and thermostat, and flush it through the thermostat housing to flush the block and heater core.

And when you burp the system you need the radiator at the highest point or else air will get stuck somewhere else so you will need to elevate the front end.

96blak54 · Jan 9, 2019

Hey you did good by asking here first! Most radiator flushes come in 3's. Usually 3 flushes to provide desired results. May i suggest vinegar for the flush!

Silver95bird · Jan 9, 2019

How thorough I would be personally would depend on the cars history. What's the mileage? What condition was the coolant in? Ever been flushed or replaced before?

If it were brown and disgusting, you're darn well right I'd flush it a ton before filling. If you're just doing a scheduled maintenance every 2-3 years, I'd probably just drain it and refill. I like a few tbsp of baking soda to reduce the acidity and neutralize it a bit. I know, it's just me .