My 2010 Sierra HD w/ 58k and dad's 99 WS6 w/ 20k are still running the original dexcool without problems. They are both on my list to change one of these years....

 

I did the same thing, I flushed mine twice, with a reverse flush on the heater core, then drove it 120 miles with only water and heater on blast, then drained it, replaced the water pump, thermostat, top and bottom rad hoses and both heater core hoses, along with a new cap. Now I want a new radiator and after another dump of green with the new rad I should have 99.5% of the dex-cool gone. I also took the reservoir tank out and cleaned it. I took about 500 small nuts and filled it with hot water and dawn and shook the hell out if it. It was the only way to get rid of the slime at the bottom. Thing looks brand new now. I saw somewhere you can use rice too lol

10 years? Wow! Well, they say if it ain't broke don't fix it, but I am sure there has to be some breakdown in the dex-cool after that long. It sure wouldn't hurt as long as you make sure there is no air in the system after a good flush. Burp the baby!

 

Does he have a Trans Am WS6 or a Formula WS6? If it is a Formula, that is one rare beast. Only 175 of those were made in 99! Only 20K? That has got to be close to mint! PICS PLEASE! lol

 

Yeah, I've been pretty negligent on maintenance on the Pontiac, except for changing oil every 3000 like clockwork. But it only has 60K miles. Still has original spark plugs, fuel filter, and even air filter. It's a garage queen and is a mechanical virgin except for brakes and tires and an EVAP Purge valve. I seldom drive it any more as the Blazer is so much more comfortable. I spent all my spare time the last three years working on the Blazer and the S10. Now that I bought the Avalanche, my wife has taken over the Blazer and we will sell her little Red 2008 Ford Ranger XLT shortbox. I was planning on driving the Pontiac for gas mileage, but found that the 4WD Avalanche gets better gas mileage than the 4WD Blazer. Go figure!


My Blazer definitely had the brown cruds and Dexcool when I got it. Believe it was probably a result of when the intake gaskets were leaking some time before I got it. Ended up replacing the engine with a rebuilt and also the radiator because of metal particles in oil cooler (apparently coolant in oil damaged bearings). Went back with 100% Dexcool mix (no tap water), new hoses, and cleaned up the reservoir so I can see the level again. No leaks and has not been a problem in a couple of years - haven't even had to add any once full was established.

 

It's just a T/A WS6 and could use a good professional polishing. The 6spd is a blast to drive though and it's parked at my place. Possession is 9/10ths of the law right??

 

Those are fun!

 

Yeah, I know the intake is bound to leak on me sooner or later. I am almost thinking about replacing the gasket before that happens just to be proactive. I DO NOT want to have to put a motor in. I hear a Felpro calling my name..

 

Still a VERY nice ride! I would love to have one!

 

Yes, yes it is