emphasis on the really. cliffs at end im at my wit's fucking end and im super pissed about this vehicle. basics: 99 Oldsmobile Bravada 4.3 chevy vortec engine full time AWD (or 4wd whatever they call it) coolant looked like and pretty much had the consistency of baby shit. Overheated on the interstate at the beginning of the month. took it to a shop, they diagnosed that the intake gaskets were trashed and needed replaced. ok, seems like that was a very common issue with these, so i got the problem solver kit from fel-pro. had those replaced along with the t-stat. the suv did ok on the interstate back from the shop. noticed it got hot at the lights afterwards. took it and had a full flush of the system. car still gets too hot. on the temp gauge it should sit at about 210, which is exactly half on the gauge. theres a mark halfway between 210 and 260 (which is the highest the gauge goes, which i guess would be about 235). the temp would read at about that 235 (3/4 on the gauge) so, i replace the t-stat under warranty hoping to hell that we just got a faulty one. the car wont go to the 260, it just goes to the 235. still does it after t-stat number 2. heres the kicker, it only does it on the interstate. driving around the city during the hottest part of the day and it does fine. when i hit the interstate it gets hot. so, i talk to some guys i know that know chevys and whatnot, and we all agree that it could be the water pump. thinking that maybe at the high speeds with the engine riding higher rpm's, the water pump just cant move the water quick enough. the check engine light was on, and one of the codes was for the coolant sensor low resistance or whatever. so, for 10 bucks, i wasnt about to just let it be. changed that too. changed the water pump. still does it. only on the fucking interstate. drove it after changing the water pump and that sensor. on the interstate, it got up to the 235 mark. got back and stopped, and the coolant is boiling out of the overflow. nowhere else just overflow. shits hot. also, what nobody else seems to understand either, the heater wont work. will blow hotter than shit air for about 10 seconds when first turned on, then goes to ambient. and stays there. no matter how long you leave it on. i figured it couldnt be the fan clutch, bc its def going, sounds like a loud ass domestic suv. and it does great sitting still at idle, and cruising at slow speeds around town (55 and under) no matter how long i leave it sitting or drive it at city speeds. cliffs: car overheated. changed intake gaskets, water pump, t-stat, coolant temp sensor. still overheats but only at interstate speeds. it cant be the fan clutch, because it does great around town sitting at stop lights. boils in and from reservoir after interstate run. the only thing i can conclude is the radiator must be clogged. i just want some confirmation, or other theories because i dont want to work on this anymore. i want it to be over. working two fucking jobs, and spent one of my two days off this month working on this fucking car, not to mention one of the few evenings as well. i mean, what the fuck else could it be? everything else has been changed. or am i missing something? i figure that baby shit coolant had to have just trashed everything up including the heater core. i dunno. im about ready to wreck it for her and call it a day.