I'm trying to change coolant on my car. I saw a video of my car where they drained the existing coolant, added and ran distilled water, drained it and then finally added coolant.
Why are they doing the distilled water step?
My owners manual doesn't say to do the distilled water step, is it necessary or a good idea, can I skip it?
I think it the answer might have something to do with impurities. If so I was low on coolant and I mixed 1 liter of coolant with 2 liters of tap water and drove for 1.5 hours. I understand this can cause minerals to get into the cooling system. Again, is a drain and replace ok or should I really be doing the distilled water step?