Milky White Substance in top of Radiator

I agree.
"...coolants typically use a phosphate/ silicate mix as the main components in their inhibitor system. Conventional inhibitors like silicates and phosphates work by forming a protective blanket that actually insulates the metals from the coolant. These inhibitors can be characterized chemically as inorganic oxides (silicates, phosphates, borates, etc.)."

 

oil in water, not the other way around, IMHO

 

It doesn't resemble ANY stop leak product I've ever seen. They're usually coppery or Barr's pellets are gooey black.

It looks like a sediment issue maybe from tap water maybe not but I don't think it's anything to worry about, just flush it good and use distilled to make up your new antifreeze.

I wouldn't worry about using tap for flushing unless you're on a well.

If you can drink it, it should be ok for flushing. My water is delish, it's prob. better than distilled.

 

Negative on the tap water. Tap water contains minerals that cause buildup over time. Best to flush with distilled whenever possible since there are no hard minerals present in it and a gallon costs all of $1 or less. Tap water is fine if that is all you have access to in an emergency or otherwise but given a choice, I wouldn't use it.

 

Mine doesn't. Not everyone lives in rocky areas.

 

If it's drinking water it does, doesn't matter where you live. Some are less than others tho. If you have to use a water softener at all, don't use it in your cooling system. Distilled water is so cheap and easy to find, why wouldn't you use it?

 

Correct coolant has not gone down at all.

 

I was talking about flushing. God this is an anal bunch.

But yes, my tap water is that good. It's tops. Refinery engineers here have said so. They demand it.

 

I'd still flush with distilled as there is some left, even when draining the block. Do as you like. I knew what you meant.

 

For what its worth how old are/were your Radiator hoses? I put a post up when i changed mine i had those tiny black specs floating around in my green coolant. Turns out my factory 200k plus mile upper hose had start to degrade and the rubber bits were getting all in the system.. Not saying thats your issue, but i did see some black bits in your pic. Can't say as far as the milky stuff... Id flush it then report back.

 

Well, ended up taking it to a radiator shop. They checked it out and said they had seen it before and was what they said was crap built up over time nothing to be worried about. My radiator cap they said was bad. So no telling what has gotten in there over time. The 1st thing he mentioned was either silicate build up or leak stop. But pressurized my coolant system and said all is well now.