car overheating
 

hey guys my car keeps over heating, it seems to overheat when on the highway, liek everytime. antifreeze then shoots out the radiator cap and my engine steams. i refilled the antifreeze and coolant but i cant drive over 60 for mroe than 15 ins w/o it overheating. any suggestions.
p.s. ive put in a new waterpump and radiator. both work fine and are not cracked.

how long have you had this car , is it a supra ?
what year ?
what color is the supra ?

Check thremostat

BHG symptoms !!!!
Do a search for BHG. Plenty of info here.

An easy check when the engine is cold is to start the car with the radiator cap off. Make sure its topped of and crank the motor, If water shoots out of the radiator then its for sure a BHG. water shooting out means compression from one or more pistons is entering the cooling system. This type of BHG will in a short time over pressurize your cooling system and force the water and coolant out of the cooling system, overfill the catch tank and soon the engine will overheat.

going to go check this out now...even tho its 1 in the am. i got my flashlight, papertowe;, and antifreeze. im ready :)

Ive seen a few cars do that without any HG problems whatsoever. All centrifugal pumps(water pump style) have to prime themselves like that. It makes a little tiny pressure wave. Which could cause water to come out. Im not debating the BHG issue, Its likely that could happen, just saying thats not exactly a good way to check.

I didn't mean a little dribble, several inches of water coming out is what I had before and by the time I drove 30 miles the catch tank was overflowing and the motor was overheating.
Also check compression, any drop between cylinders is another sign that pressure is escaping.

no loss of compression and no water at all comming out. that little plastic tank in front of my car. is that the catch tank? should i fill it up? or leave it empty?

well then
 

Start the car when cold with the cap off again, let it warm up and see if the water flows after the thermostat opens up. Rev the motor and look at the flow through the filler neck, it should flow faster when the engine is revved up. You didn't mention checking the thermostat yet. Its possible like blitzmkiii
said that it could be stuck. If after you check this and there is no flow then the thermostat is stuck or some other obstuction. Some people run without a thermostat but for todays fuel injected vehicles its not recommended.
You should fill the tank up to the cold line.