[Kevin]

My 87 turbo overheats when i drive on the freeway for about an hour. it seems like coolent is coming out the overflow and all over the intercooler. I drove it back to my mechanic and he said the radiator was leaking. so he replaced the rad and the thermostat. i told him i think it might be the head gasket. he said that it shouldnt be because there should be tons of white smoke coming out the exhaust. so i let him be since hes the expert and im not. i took it back on the freeway... and sure enough after about an hour... the temp started climbing up again. up to max. so i pulled into a gas station. carefully removed the rad cap and added 2 litres of coolent. i lost a bunch out of the overflow again... it was all over the intercooler. after adding the coolent. it was back down to normal temp again. I drove it back to him and said it overheated again. i said i really think its a bhg. he said he'd take a closer look. the next day i called him up and he said he fixed the problem. i asked him wat was wrong. he said a bunch of things i could barely understand him because the phones were fuzzy. but he said that he ran it for over 3 hours and it was fine so it is all good. i am not sure if he actually drove it at freeway speeds though. i have a feeling that he just idled it for 3 hours. what do you think i should do because i need to drive it 4 hours.. cuz i live 400km or 250 miles away. i was thinking about just giving it a shot and try to take the car home.. if it overheated again i'd pull into a gas station.. let it cooldown a bit and add more coolant. the problem seems to be losing coolant. the oil isnt milky and there doesnt seem to be oil in the coolant. i dont wanna tow it cuz i dont have that kinda money. any suggestions? And sorry for the long ass write up.
The car drives around town just fine. just overheats at freeway speeds.