rust in the water pump, rust on thermostat

[Clavo106]

Originally Posted by special-K

It may have been done by now. I had to do the trucks I had in the '90s. Hardened valve seats cure the issues. I don't know where you're at with this truck or what you want out of it. If you just basiclly want to run it for now, go ahead and flush it real good and see what happens, maybe nothing. My response may have been a bit dramatic. I saw you mention new motor and responded to that.
I've had vehicles with chronic rusty coolant, including a '90 Blazer I bought new. By the second winter the heat wasn't that good. That's when I noticed the rusty coolant. I had it for 193k and replaced the heater core three times and a couple or three radiators. I think the pump went that many times, too. I flushed it, had Jiffy Lube flush it for an hour or more, did the BG back flush, etc. It was just bound to be an issue no matter what.I wondered how the inside got rusty on a new motor

BY CHANCE YOU where not running GM's . DEX coolant . Orange in color.. some of my friends that work at gm dealers say it has to do with the cleaning power of the solution... ?? not shure y but it just glycol.. but have heard lot of guys with problems like that. because they ran dex cool. i know dex has more life span but thats it. my caddi had dex from factory turn th overflow a nasty dark Orange.. most guy switch over to regular green coolant witch thats what I did. it look alot better....