Hey all, I'm new here.

I have an '05 Blazer, 4.3L V6 with 4x4, about 112k miles. Last Wednesday, I was having temperature issues when I was leaving college to go home for Easter break. Not even two minutes after I had gotten on the freeway, my check engine light came on and the temperature gauge had increased significantly. Had checked my fluids before I even turned on the car and my coolant was full. Before getting on the freeway the engine had ran probably about 5-10 minutes in total and was at normal levels (about 200 degrees or so). Temperatures increased to 240-250 and the check gauges light came on, so I pulled over. I decided to double back to college and have my parents picked me up, and that was about a 7 minute drive, temperatures still very high but no overheating. When I got back, the thing was practically puking out coolant near the radiator, there was a huge puddle on the blacktop. Waited about an hour and fifteen minutes for my parents to arrive, and my dad gave it a look. During my wait, the leaking slowed and eventually stopped. When my dad started it and gave it a look, it was running relatively hot at idle, and the leak started again but it wasn't as severe. We left it at college for break, and my dad picked it up this morning and took it home on a trailer.

Before taking anything apart, he took it for a drive and kept a close watch on the temperature gauge. He had driven it over 40 miles, and the temperatures didn't spike once. Everything ran normally. Forgot to ask him if the check engine light was still there, but regardless there wasn't even an issue. No leaking either. I have no clue what could have changed because the vehicle just sat there in the parking lot for five days. We both think it might have been the thermostat getting stuck causing the issue, but would something like that just fix itself out of nowhere? I wouldn't believe so. I'm pretty confused, anyone have any insight into what this could be?

 

Where was it leaking?

Any recent work on the truck?

Have the LIM gaskets been replaced?

Do you hear gurgling in the dash?

Overheating can be a lot of things:

1. Air in the system
2. Clogged system
3. Thermostat
4. Radiator
5. Water pump
6. Radiator Fan
7. Blown head gasket

And welcome to the forum.

George

 

It might have gotten stuck once but I wouldn't rule out the possibility of a repeat and I'd change the thermostat and keep an eye on everything else as well. Try to run it around close to home so you're not stuck far away should it act up again.