If you got this stuff in your vehicle, get it out, and flush your system very well. Especially the heater core feed. Do not stop flushing until you get a pinkish, brownish plug.

Do not go by how good the reservoir coolant looks (you probably have visible brown particulates in there anyway), or the coolant under the radiator cap. I don't care either if you bought your box new. I bought my 1 ton new, kept the motor care immaculate, and got the plug. That made 4 'GM Red' equipped vehicles, and 4 plugs, including one 'pedigreed' vehicle. As far as I'm concerned, case closed. Google it too.

GET IT OUT, and replace it.

 

True story^^^^^^^ any GM extended life coolant causes packing or gelling of coolant on or around the intake gaskets and WILL cause the to get hot(from lack of proper cooling lubrication) and burn "hot spots" in them causing intake gasket leak( if your coolant keeps dissapearing and you dont see a leak) you probably have an lower intake gasket leaking[:@]
Also it will plug heater cores and radiators as well[&o]

 

Question, we have a '06 Silverado. The coolant is pink, and the dealer told us not to mix other coolants with it, such as Prestone. Could mixing products be the cause of the "plug", or is the GM coolant the prob?

 

So is this a common known issue? So should I not run the GM stuff that is in my Corvette and Tahoe?

 

No.

Like I said about my '02 Express 1-ton (bought NEW), I kept it in absolutely immaculate condition. Never driven hard, etc., etc., and it developed the plug in two years. No mixing necessary there, c3... Did it all by itself. 4 times on 4 GM Red (pink)- equipped vehicles.

I was lucky it did not lead to serious cooling issues.

Google it t'pilot. You'll see quite a few hits on this issue, I'm sure...

 

for C3 you cant mix the coolants because regular green coolant run on a glycol and PH,and GM coolant runs on a nitrate system for all the anti rust corosion and gel inhibitors , two mixes that cause instant gelling, also water will gel instantly when mixed with GMH.O.A.T. coolant it is a very bad problem in many 3400 3600 and 3800 engins forund in buicks and pontiacs aswell about a 600-800 dollar repair[:@]