I have 92K on my ’03 and have never done anything to the cooling system. This past weekend the low coolant light came on for about 3 seconds right after startup, then went off. After shutting off and restarting a few times, the light never came back on ( I only saw it that one time). After checking the reservoir, I had to add about 1.5 quarts of Dex-Cool. I have put on another 400 miles since then and the level seems to be staying the same. I have looked all over and have found so signs of a coolant leak, nor do I smell any coolant odors. My question is: is it normal for the truck to use a bit of AF in that may miles and it’s no biggie, or should I be worried?

Don't know if this helps, but had the samr thing, low coolant light has come on randomly maybe 3x since I bought the truck. Reservoir wa below the full cold mark by 1-2 qts. Last week the low coolant light came on each time it was started. Added a little and now no light and level is staying the same.
I wouldn't be worried if you only had to add coolant 1x in 92k miles as long as it's still not drinking any.

That's what I'm guessing. I know I drive it pretty hard every weekend on the-way going to the boat 500 miles round trip (@ 90mp+). I'm sure there had to be some evaporation in 92k.

You might want to think about changing the coolant since you are nearing the 100K mark.

From what the manual says, Dex-cool is good for 150k.

Better to change it @100K while the fluid is less acidtic (sp). Even though Dex is okay for 150 per manufactuer reccomendations.

I had to add about 1.5 quarts shortly after I bought my truck new. I think GM was trying to save costs by not filling the container to full capacity. :)

4B

Check all your clamps. Had the same problem on the suburban at about 110k. Found one of the clamps down low (hard to see and reach) snapped as soon as I tried to tighten it from being rusted. Put on a new clamp and all was well with no lost coolant.

From what the manual says, Dex-cool is good for 150k.

I understand that, but we (forum members) go above and beyond what the manual says in an attempt to maximize the life of our trucks. Personally, the money spent at tighter intervals is cheap insurance and gives me piece of mind when I think about the initial cost of these rigs.

So, I will change the oil every 5K, install a new spin-on for the Alli at 5K, replace the fuel filter every 10K, and so on. When I got close to 100K, I had the dealership flush/fill the coolant, power steering fluid, and brake fluid.

-Wardster

QUestion?
Not to hijack, but is the lifespan of the coolant just as time dependent as it is on hrs of use?
I've always changed the coolant in vehicles when they were about 3yrs old, once the green wasn't so "green" anymore.
Never had a vehicle w/ the fancy Dexcool and my truck's 4 yrs old, but low miles. Was planning on changing it soon, as I'll probably keep the truck a while. Coolant still looks good though.
Iknow.....cheap insurance, but is it necessary?

Did you chk the waterpump weephole? Mine would lose coolant inconsistantly and could only see it after the system was pressurized. Another place to look would be the passenger side coolant line to the turbo? There was a thread about pinhole leakage on that hose that'd show up when pressurized and wiggled ~ caution can scald oneself.

I have put 700-800 hard drivin, 92° weather miles on it since I had to fill it up and it hasen't moved yet. Seems to be staying in the same spot. I gotta take it in for the AC not blowing super cold air next week, so I'll have them flush her out.

I thought GM changed the 150k replacement on dexcool to 100k. They were having some problems with dexcool attacking plastic parts in the cooling system as the coolant got older. GM wouldn't admit a problem or fault but I thought they did ammend their policy.

Injector sleeve going bad maybe?

I had to add about 2 quarts the other day, all i had in the truck was the Green stuff, should i Have it flushed and changed, it has 79,000 on it

Check Turbocharger water supply line.