I bought 50/50 expensive quality coolant. Now learn there is a litre or so still in engine. I’m going to do 4 fill-dumps with distilled water, and then finish with the 50/50 coolant. Do I need some concentrate too, to offset the fluid in the engine block? I’m not going to attempt to drain the block!
is this a Big enough issue worth worry?
thank you.
I’m going to do 4 fill-dumps with distilled water,
that's a waste of money. You can use tap water for your flushes.
Do I need some concentrate too,
I buy concentrate ONLY. It's far cheaper than getting the premix.
Add however much concentrate you need, and then top up with water.
Coolant perfect ratio necessary?
All that matters is that the concentration is at least 50% (to get the anti-corrosion additives), and that it's strong enough to not freeze (it should tell you on the bottle). Use a coolant tester for that ($10 at any parts store).
I think most people just drain the radiator, and fill back up with 50/50 and call it good for a few years.
I did do an old 98 f-150 that had been sitting for for many years, and was on it's original coolant at 58k miles. I did drain and fill it like crazy, and did a flush, because it was flat out nasty. When you have nothing but distilled water in it, you want to do a drain and then fill with non diluted coolant.
Don't worry about perfect, you can get a tester for a few dollars, and make sure it is pretty good.
