Parents have never changed coolant

[Moab]

All I can tell you is at 150,000 miles on my 2003 Chevy Cavalier the Dex Cool was getting a sticky/gummy residue around the top of the coolant overflow bottle once the cap was removed. My mechanic warned me about Dex Cool. I completely flushed my cooling system, replaced the coolant overflow cap with a new one from the dealer and refilled the cooling system with new Prestone Dex Cool last year. The car now has 170,000 miles on it and I plan on changing the water pump this summer before it fails. I will switch the car over to Prestone green antifreeze at that time.

I like GM products! However when it comes to the recommended fluid change intervals in any car manufacturers owners manuals I personally think it is better to change all fluids earlier than the owners manual states to do so. I'm big on preventative maintenance.

 

[A1BadPizzaGuy]

I have 156,000 miles on a 2004 Colorado. The dex cool still looks very good. A clear, bright orange/red, no buildup in the overflow bottle or under the rad cap. The truck runs at a consistent temperature, and the heat works very well. Similarly to what SteveSRT8 says, I've basically decided to leave the coolant in there until I notice a problem, at which point I'll clean and flush the system and replace with probably green coolant just because I'm paranoid about risking mixing air with dex cool. Maybe it's irresponsible, but my truck runs perfectly.

As for the OP, I think as long as the coolant looks good, and there haven't been any obvious problems or leaks, leaving the coolant in those vehicles will be fine. Upsetting your dad may be a larger problem than leaving the coolant in those vehicles.

Sorry, I should add, except for any warranty purposes. If you or your parents are concerned about warranty claims, do what the owner's manuals or manufacturers say. Although it doesn't really sound like that's too much of a concern.

 

[Moab]

My 2003 Cavalier has always ran like new other than I did have to replace the fuel pump in this car last year. Never any overheating problems. The original factory fill Dex Cool looked clean and clear at 150,000 miles, but there was a sticky gummy residue forming at the top of the overflow bottle on my car, so I flushed it and filled with new. I also replaced the overflow cap with a new one. They eventually fail and will not hold pressure. How many cars engines were ruined because the radiator/overflow cap failed and the car overheated? Who knows, but I am sure the numbers are extremely high for such a cheap part.

 

[SteveSRT8]

Originally Posted By: Ken2
Originally Posted By: SteveSRT8
After lunch with a G team engineer from GM, we now change the coolant only after component failure. I still have an 05 that has never been touched, but normally we put nearly 200k miles on them before something quits and we need to open the system.

Dex is that good.

But, if the coolant was changed more frequently, would some of those component failures be adverted? Keep in mind that GM is in the business of selling parts as well as selling replacement vehicles.


IME you are unlikely to nurse many water pumps much past 200k miles in anything, much less in a 6.0 liter gas motor in a 3500 Savana! We routinely exceed this.