I'm sure this has come up before, but couldn't find what I needed.
I'm doing routine coolant flush and fill on an '97 MKV VTEC 4-cyl. about 140k miles..
1. Should I use radiator flush product to clean the block?
2. The radiator drain seems a little wonky, it turns very tight and never really flows out nice. If I keep loosening it, will it come out/off so I can clean or repair it? (in hind site, should have just pulled the lower hose, damn Haynes manual)

 

Radiator drain plug comes all the way out. Little plastic plug with rubber O-ring, I always take it out to drain faster.

Radiator flush product? I would look inside radiator neck and/or T-stat housing to judge whether it's dirty enough to need that. If clean, I guess I'd just rinse really good & then refill. Crusty or sludge in there, THEN use a cleaner.

 

Regular over the counter Liquid Drano (not the foaming stuff) works well, but be sure the thoroughly flush the system with clean water and drain prior to adding final coolant. Beware, you need to make sure that prior to draining the system you need to make sure the interior heat is set to high, otherwise you will not fully drain the system as coolant will remain in the heater core circuit.

 

Drano is lye = sodium hydroxide. It rapidly corrodes aluminum, the metal that the radiator and engine are made of. Don't even consider using drain cleaner of any type to flush a radiator.

 

^^^your first post "themess."
Hope you stay around.

 

Thanks!