1997 bmw z3 conv. 1.9 overheated, changed radiator, new thermostat, hoses car still overheating , fill radiator w/water but water does not seen to go through , released air pressure from radiator and car it seemed to keep from reaching the red boiling mark, could it need another thermostate & a water pump?

Hoses wear out , replace it . That hose is under a lot of pressure and heat and everything wears out and has a life. I would say that was a helluva hose to last that long and would suggest you look at all your hoses and belts especially if they have never been replaced.

Change thermostat since you change coolant. Also did you fluch radiator and clean the fins on radiator? Make sure new fan clutch works and also that you have proper pressure cap on radiator

You may have still air lock,if not could be plug radiator.

Well Michael put your hand on radiator upper hose and then the lower hose right after car warms up and just starts overheating is there a temperature difference if so one of two things is going on thermostat not opening even though it is new or there is still an air bubble in the cooling system if nthere is no difference and still overheating might have to explore headgasket being blown

Verify radiator is clear and getting air through it. Once engine starts to get warm, spray radiator down with cool water and see if the temp goes down.

Thanks for choosing FixYa and welcome to the site. The most common issue to overheating is a stuck thermostat or a bad one. Next, would be the water pump. You could need a new coolant cap, which only cost a few bucks. You want to make sure that your fans are kicking on correctly. If they are not, check the fuses. If the fuses are good, you may have a bad fan or a bad wire. Make sure there is no coolant leaking. Sometimes, coolant can leak into the oil and is not easily visible to the eye. You may want to check your radiator also. It is possible that you have a bad coolant sensor as well. If your check engine light is on, you should take it to Autozone or Advanced and have it scanned. They do this for free and it might lead to what is causing your car to overheat. I hope this helps you.

I too had similar problem when replacing the thermostat on my Z3. My advice is top up with more coolant and check the level.

check the thermostat, it's where the top radiator hose meets the motor in a housing

Change thermostat.

Two possiblities; a blown head gasket, or a freeze plug leaking. If possible take it to a trusted shop and have the pressure checked on the radiator, they can tell you if your radiator is stopped up, or the freeze plug is leaking, and if it's blowing back in the radiator when you remove the cap then it's a blown head gasket.