Trouble with cooling system 1996 Blazer

The wife was driving the Blazer today and noticed that, at one point, it started to overheat. It then started to cool off, possibly because she was then at highway speeds.
At home, I checked the oil level and it looked good. I checked the coolant reservoir and found it to be very dry, with a mud like substance at the bottom. I put some water/antifreeze in and it's still very muddy.
Any ideas what this is?
A few days ago I heard a fluttering-like noise coming from the area underneath the glove box. It started and ended very quickly.
Thanks in adavance for your help!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I checked the oil level and it looked

My '94 Suburban K1500 5.7L had a mysterious disappearing coolant condtion that first manifested itself in the way yours did. Overheating, coolant low, gurgling from heater core the odd time due to air in the system. This brute had the rear heater with miles of heater hose that airlocked and blew cold in winter (which was when it happened). Turned out to be the usual suspect....bad intake gasket at drivers rear slowly dribbling coolant down by the oil filter. Can happen at other side too. Sounds like you need a flush and rinse, pressure test and refill. Might be the intake, might be just a leaking hose or rad.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
so what does the coolant look like that's in the radiator?
sounds like you may need to have the radiator cleaned by a radiator shop, and flush your entire system.
"muddy" coolant is not good.
On Sat, 16 Jun 2007 21:21:24 GMT, John Falcon

----------- Elbert snipped-for-privacy@me.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That is for sure. ----------------- TheSnoMan.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.