Coolant rust

[davepl]

Had to drain the coolant to change over to tower clamps, but noticed it was quite brown (and started out green, as Prestone).

This is odd because:
- Engine was hot tanked
- Engine was baked
- New radiator
- New heater core
- All new hoses

So the only old part I can think of is the water pump!

It's always had a coolant mix in it, never plain water. Where the heck could I get enough rust to color the coolant that rusty brown color? Or does it take very little to cause that?

[Dustytrix]

It doesn't take a lot of rust to show up. But did you say coolant only, never added water to coolant?

[4 Wheelin Fudpucker]

If Bars leak was ever added, it leaches into new coolant.
Its brown in color too.

[midniteblues]

I would say your ok.
My thoughts are
With a fresh hot tanked engine it will develop some rust hot tanking is a great process but it "can" still leave some sediment behind depending on how long it was in the tank and how much crud was in the block before hand.

Then filling the block and circulation of coolant stirs it up.

Think of a cast iron fry pan if it's clean and not seasoned let some water sit in it an it will rust on the surface.
It's just what happens.
I bet if you flushed it out now the brown Ness of the coolant wouldn't come back for a while since you've knocked loose the only junk that might have been in there.

Oh and don't forget to use distilled water for its low acidity/mineral level.

These bb hold ALOT of water and there is a lot of surface area in the block.

[hamjet]

I saw the same thing with my engine. new w pump, hot tanked 2 times, heads hot tanked 1 time, new rad, hoses, I ran it on an engine stand with distilled water till cam break in, and maybe 3 hours total till I drained it to install in the truck and water came out rusty looking. The out side of the engine looked very clean as did the cam and crank area when I picked it up from the machine shop, but I could still see in the water ports where the water pump bolts and it still looked brown in there before build..

[davepl]

Yeah, now I wish I would have flushed it, but didn't expect it would benefit at the time! Thanks for the info and reassurance.

To be clear I actually did say I always had a coolant MIX in it - 60 distilled water and 40 prestone, more or less. And not the "already cut with water for you" stuff.

[wahl4m]

sometimes a can of 'water pump " lube helps on start -up or soluble oil ? which is available if you know somebody that works in a machine shop,around saws or milling machines ? i always liked the "coolent" type of filters on some of the big diesel trucks !

[snipescastle2]

I'd try flushing your coolant out, run some distilled water with a 1/2 of liquid dishwasher detergent in the mix, drive for a day, get it up to operating temperature, drain, flush repeat till it's clear, then add your coolant and go, just make sure you run the heater full blast to flush it and all, the hoses of the junk. You'd be surprised at all the dirt/rust, Etc... comes out.......
HTH,
Ben