GMCtrk

iTrader: (27)

Was out on my old man's ranch out in the middle of nowhere. Temps were at 0F.

Forgot to check coolant before leaving Texas. Got up this morning, fired it up and it idled for about 30 mins while i got ready. Just before i was about to leave, saw a coolant geiser from the front end on the right. Temp gauge was pegged.

Noticed no heat coming from the vents and coolant boiling in the tank.

I'm thinking water pump went out but that seems random. Didn't see any obvious radiator damage, but wondering if the core of endtank could have cracked.

No obvious white smoke out the tailpipe. Do the 2002s have the issue with heads cracking?

Any input appreciated.

1FastBrick

iTrader: (17)

If there 706's or if the coolant system wasn't properly maintained, yes they could crack.

I remember the TSB saying like 2000-2006 on the Tahoe and Suburban

About20ninj45

Castec heads if they are stock

GMCtrk

iTrader: (27)

Update. Truck was refilled with coolant. Drove the tahoe 11 hrs from MO to TX, not a single issue. I'm still at somewhat of a loss why it overheated. You'd think if the coolant froze it would have cracked something.

Averaged approximately 17.7 mpg doing 75. Seems low to me. 5.3/3.42s.

FFDP

iTrader: (2)

Lower your speed is what I'd do.

I get my best mpg at 68-70mph in my truck, I have a 5.3/3.42's, though the newer GEN 4 engine. On my trips to the cabin I can get 20-21 there, add the little bit of driving around and the avg drops to around 19 by the time I get home.

kbracing96

iTrader: (26)

It froze and wasn't circulating, put more antifreeze in it if you're gonna be in the cold! lol

GMCtrk

iTrader: (27)

It's not really anything that bothers me, just an observation.

My old excab with 6.0 and 3.42s would pull 23 mpg at 70. I would have thought the I'd do better than 17 in the Tahoe even allowing the weight difference.

Speed limit in rural TX is 75-80.

GMCtrk

iTrader: (27)

If it froze how do you explain coolant boiling in the reservoir?

1994Vmax

iTrader: (4)

If it froze in the rad of the truck you will have no flow.. coolant expands with thermal expansion and pressures up. .. pop goes the weasel. The trucks thermostat won't even let coolant flow in any amount before it opens so the heat is going to be nowhere near the ice slug. Not to mention water is an excellent thermal barrier...... over 200 degrees at the engine will do nothing to a frozen rad and or hose. Then when it sat it thawed out from residual heat and away you went. Trust me.. I work in colder climates and it still baffles people how a transmitter attached to 650 F steam line will freeze solid a foot from the 650 degree temp source... Pretty simple when there is no flow and it's simply dead headed it won't thaw out...

kbracing96

iTrader: (26)

^^^ What he said, lol.

Probable froze or slushed in the radiator or upper hose and couldn't flow. So block got hot, open thermostat and boiled back up the hose into the coolant tank. That was the only way it could push the steam out.