Coolant, Deposits and Flush?

[bdea]

Should I worry about these white crusty deposits on top of the radiator core. They are not floating around and the tubes are clear of any buildup.

Was this caused by residual tap water in block while I flushed it (forming calcium carbonate?) and not the distilled water added with coolant to fill the system?

I can scrape the deposits it off with a screw driver.

Should I use a flush and what product?

Temperatures @82 C, 90 if sitting but goes down during driving.

Coolant changed religiously every 3 years except for 8 year sleep from 2011 -19, when I retired.

Used Presone (Yellow Colored) All Vehicle Antifreeze.

Which IAT Coolant should I use?
What Brand should I use in the USA?

Peak All 10x More Inhibitors/ 10+ years /300,000 mi or the previous Prestone.

Many Thanks, Brad

[m750rider]

I would not use a commercially available flush as in my experience they don't do much. If you want the radiator cleaned, remove it, take it to a shop and have them clean it and test it, verify it has no leaks and holds pressure.

I've used Prestone for many years without trouble. I don't think anything special is needed.

The deposits you see on top and shown in the picture will be removed with cleaning, but if you are maintaining 82C while running and 90C standing your radiator is doing fine.