Massey
Full Member
Hey guys! OK this one has me stumped pretty good. Here is what's up. 2004 Avalanche with 377K on the clock. Yesterday the radiator blew up on me while on the freeway. The temp got a bit over 210 when I finally found a safe place to pull over and get a tow. It didn't run bad or anything, I just got antifreeze sprayed all over my windshield and all down the left side of the truck. Blew right at the tank seam... pretty typical.
Got new rads... Got 2 gallons of DexCool concentrate, and went to work. Lower heater hose with the Y in it broke as I was taking things apart... Great more $$$ out of my pocket. I had green AF in the truck so I flushed it all out till water came out clear, no more green. Everything went together perfectly, no issues. I started the truck after the overflow was full and topped it off after it sucked some down. The engine only got to about 150° idling. OK so off to a test drive and I then got to a whopping 158°. Temps were verified by an Autel scanner and the gauge also was showing really low. So I figured that my T-stat was bad and my slight overheat may have killed it open. Today new T-stat (187°), more new coolant (can capture it, cant recover it... GRRR more $$$). Now it gets to about 174° again verified by the scan tool. I also replaced the sensor on the left head, same business with the temps. Gauge in the dash used to show just below 210°, just like every LS engine I have ever owned. I drove 60+ miles home tonight and the temps stayed steady. I get heat, but not cook you out of the truck heat that I had just yesterday before it blew. Water pump is newer and nothing is leaking anywhere. No coolant smell in the exhaust, no steam from the exhaust after the truck gets luke warm. I do not have a IR temp scanner at the moment, I need to get new batteries so I couldn't say what the block or radiator temp are. Nothing feels insanely hot, and I can hold onto the hoses without being uncomfortable.
Old T-stay was OEM or at least an AC Delco unit, and it was not stuck open this morning. I could move it open easily as well. The seal did look horrible, and left black on my hands when I touched it, so good call on the replacement anyway. Yes I do see flow in my overflow, I get the small upper hose squirting coolant back into the overflow and when looking in the filler you can see the coolant circulating. Oh and the radiator was OEM as well. It lived a good long life!
Any clue as to my issue? My truck is a engine powered fan type, and my fan clutch seems to be working well. Engine runs well, no loss or gain of power, just normal running.
Got new rads... Got 2 gallons of DexCool concentrate, and went to work. Lower heater hose with the Y in it broke as I was taking things apart... Great more $$$ out of my pocket. I had green AF in the truck so I flushed it all out till water came out clear, no more green. Everything went together perfectly, no issues. I started the truck after the overflow was full and topped it off after it sucked some down. The engine only got to about 150° idling. OK so off to a test drive and I then got to a whopping 158°. Temps were verified by an Autel scanner and the gauge also was showing really low. So I figured that my T-stat was bad and my slight overheat may have killed it open. Today new T-stat (187°), more new coolant (can capture it, cant recover it... GRRR more $$$). Now it gets to about 174° again verified by the scan tool. I also replaced the sensor on the left head, same business with the temps. Gauge in the dash used to show just below 210°, just like every LS engine I have ever owned. I drove 60+ miles home tonight and the temps stayed steady. I get heat, but not cook you out of the truck heat that I had just yesterday before it blew. Water pump is newer and nothing is leaking anywhere. No coolant smell in the exhaust, no steam from the exhaust after the truck gets luke warm. I do not have a IR temp scanner at the moment, I need to get new batteries so I couldn't say what the block or radiator temp are. Nothing feels insanely hot, and I can hold onto the hoses without being uncomfortable.
Old T-stay was OEM or at least an AC Delco unit, and it was not stuck open this morning. I could move it open easily as well. The seal did look horrible, and left black on my hands when I touched it, so good call on the replacement anyway. Yes I do see flow in my overflow, I get the small upper hose squirting coolant back into the overflow and when looking in the filler you can see the coolant circulating. Oh and the radiator was OEM as well. It lived a good long life!
Any clue as to my issue? My truck is a engine powered fan type, and my fan clutch seems to be working well. Engine runs well, no loss or gain of power, just normal running.