I was wondering what that would look like?
Reason I question it is because I took my 1999 'burb (5.7L Vortec) in for a service on the tranny and transfer case. Glad I did because they found the transfercase was overfilled due to a bad seal between the two. Anyway, they noticed I had an error code, which is due to a faulty O2 sensor or cat, but they wanted to make sure it wasn't a tranny code. Well the truck started to overheat. Temp gauge just below the red, but didn't seem overtly hot.
I was standing there at this point and one of the mechanics said the antifreeze was full earlier when he checked it, which now I wonder why they'd check that. Maybe just being thorough. They checked again and it was now almost looking empty. It hadn't been overheating on me prior to this, but I live 2 miles so I drove home and though it was a bit hot, it never reached the red nor did it ever seem to really smoke as I would think on an overheating V8. In fact when I got home, I took the radiator cap off again and no steam came out. I didn't even notice any when they opened it up. I filled up with about 2+ gallons of antifreeze and water. It seemed like it kept wanting more in small quantities, so I decided I'd let it sit overnight and check after driving the next day.
Well while all of this was going on, I decided to check the oil level, as I'm due for a change and the oil level is really high on the dipstick. At times well over a foot up, with car running and not running. I didn't notice any froth or bubbles, but it does look pretty thin and transparent.
I checked again about an hour later and the radiator looks about a gallon or so low.
At this point I started it up and tried to check for white smoke, but it's dark and coldish (50's), so I couldn't tell, though I didn't notice any. I do recall seeing white coming out when I got to the mechanics, but I didn't think anything of it because of the temp. In fact at that point, I could see the heat coming off the engine as well. Nothing looked to be out of ordinary for the temp.
I tried looking into the oil fill cap, but couldn't tell much. There was some clear moisture around the lip of that. I figure that is just condensation from the coldish temps. Like I said it's clear, not milky like I'd think if it was an antifreeze mix.
Also, the oil pressure is right at 40, which is normal for this truck. One other thing, which may or may not relate, my air conditioner started acting up recently, as in it wouldn't cool right. I've been trying to troubleshoot that, but with temps dropping, it hasn't been a priority.
The truck also seemed to run fine coming home.
Sorry for the length, but I didn't want to miss anything. Does all sound ok for a hotish truck or does it seem like something else?