Rust colored & thick coolant in overflow tank?

[joezaier56]

2000 STS with Rust colored & "thick" engine coolant in "Over-flow" tank, can anyone give me the most likely causes for this?

[the recluse]

Piss poor/lack of coolant. Flush, reverse flush, and add coolant.

[Red.1998.SLS]

Another possibility is Coolant tabs. these can cause color to change and some residue in tank.

[Ranger]

Red is correct. Don't panic, it's normal on the cars that GM was using the tabs on. It does not indicate poor maintenance. In fact, just the opposite.

P.S. Gm no longer uses them.

[the recluse]

Still, guys, GM stopped using tabs a while now....coolant's got to be old...

[Red.1998.SLS]

He just bought this car per his private message, my Cadillac Dealership asked if I wanted the tabs in and I said yes, and that was about 2 1/2 months ago, their is a pretty good debate on if you should still use them, my dad has always used them so I also did, his coolant could be old, if it is he needs to change it, but really no reason to worry too bad.

[joezaier56]

Someone mentioned to be about pulling a DOT code? How do I go about this and what would I actually be looking for to determine what my issue is? To be a little more clear on my original post, coolant appeared to overflow or come out from both the overflow cap AND to the left of the engine bay side near the bottom corner near the radiator, appreciate some further insight on this, just not trying to get robbed by the repair shop?!?!

[Ranger]

Someone may have put the tabs in the tank. They just settle down to the bottom and stay there.

[Ranger]

DOT code? Do you mean DTC (Diagnostic Trouble Code)? See the sticky at the top of the page.

You did not mention any overflow or over heating.

[joezaier56]

But "MUD THICK" is normal for these model sevilles and wouldn't be an issue with fluid flow threw things like the radiator, thermostat and such!!? And my temp guage is now starting to fluctuate between 12 oclock and the 2 oclock while highway driving

[joezaier56]

Sorry I meant the DTC code. How do I retrieve this and what exactly am I looking for??

[Red.1998.SLS]

Like I said before, I would get the coolant changed, by someone who knows what they are doing, see if you problem goes away. Mud thick seems too thick to me, if you have never changed the coolant do it, had you ever looked at it prior to this, how long has it been mud thick?

[Ranger]

The sticky at the top of the page will tell you how to pull them and where to go for the definitions, but I doubt you'll find anything on this. First thing I would do is check the purge line for coolant flow. If that's OK, then I'd clean that muck out of the tank and see if that helps stabilize the temperature. It may be clogging the line to and from the tank to the cooling system. If not, do a block test to test the coolant for exhaust gases.

[N*Caddy]

The coolant is pink-red to bright orange depending on the batch (the die concentration might vary). Coolant tab free still looks some how muddy. You should add 1-3 tabs (I personally put 1), the tabs are brown-gray and 1 maximum 2 dissolved in the coolant will make little difference in the aspect or the coolant. The suspended particles do tend to clog in the low flow areas, also if you have a small leak will tend to create a white-ish residue in the area (that’s what is clogging the leak).
My coolant is 13 months old, one month ago I removed the purge line and let it run into a plastic bottle (looking for abnormal flow and bubbles) and eventually when the bottle filled up it was looking like a freshly made whine (but a red-pinkish-orange-ish) color.
Definitely looks nothing like something natural (say like rusted water would normally look).

[Ranger]

That whitish residue is from dried Dex, not the sealant tabs.