We talked about this a month or so ago on this forum, but it's come
back to haunt me again. So I thought I'd give it another shot.
A couple of weeks before leaving for Nationals last year, I took my
'96 Chebby S-10 (4.3L Vortec V-6) in to the local Xpress Lube for a
routine oil change. While going through the normal check, they found
gobs of red "mud" in my radiator. It looked like somebody had dumped
a shovel full of good ol' Louisiana red dirt into the cooling system.
They scraped out everything they could get to and then did three
complete flushes of the cooling system before they were satisfied
enough to fill it back up with DexCool antifreeze and water for my
It worked fine until a couple of weeks ago (about four months since
the triple-flush) Then the temperature gauge started to go ballistic
while the air coming out of the heater ducts was still cold. A
classic case of a stuck thermostat, I thought, so I changed that bad
boy yesterday. Then I got hot air out of the heater ducts and the
temperature gauge STILL went ballistic. The coolant recovery tank was
still full of nice bright red DexCool antifreeze mix. So I popped the
main radiator cap today and there, to my surprise, was another load of
that red mud!!!!
Obviously, the overflow tube from the radiator neck to the coolant
recovery tank was clogged with the stuff (which is why everything
looked fine in the coolant recovery tank) so I blew that little tube
out with an air hose. Then I flushed the whole cooling system again
and refilled it with water and DexCool.
Everything's fine, now. It's not overheating and everything seems to
be working according to Hoyle.
BUT, the question remains, where in the hell is this red mud coming
from and how in the world can I keep it from recurring?!?
According to GM, the cooling system shouldn't need ANY maintenance for
5 years or 100,000 miles as long as you add only a DexCool
antifreeze/water mix when needed. But, my truck is only four years
old, has only 78,000 miles on the clock, and this is the SECOND bout
I've had with this red mud.
Your input would be GREATLY appreciated.
John (Old Fartz & TLS #37) Lieberman