It may be the water pump.
Yes a bad thermostat would cause overheating in any car. A thermostat regulates the temperature.
Head gaskets!!
Check the thermostat. Another reason could be the head gaskets are blown.
Have the head gaskets checked and intake manifold gaskets checked for leaks. The 3.4's are known for head and intake leaks! Or a bad thermostat.
First start would be to check the antifreeze and if that is full then I would check into the Thermostat and make sure it is stuck. If it is Full and heats up real fast then my guess would be the thermostat.
it could possibly have either a blown head gasket or intake manifold gaskets leaking
most likely the thermostat, but these vans also have a history of blowing head gaskets...... It would help if you described symptoms
check your water pump. As well as your thermostat housing, and any coolant hoses/connections.
have you had the head gaskets replaced you might have blown head gaskets or warped heads on the block this is a costly repair check your water for oil or check your oil for water this will help to determin if they are ... have you had the head gaskets replaced you might have blown head gaskets or warped heads on the block this is a costly repair check your water for oil or check your oil for water this will help to determin if they are ...
If you replaced the head gaskets, thermostat, and the water pump and it is still overheating then I would ask about the fan. If it is not the fan, then I would say that you have at least one bad head, if not two. But that is just a guess. A mechanic will pressure test the system and will be able to tell you more. Is the radiator restricted?
say you wanted to buy a painting he would say it was genuine and a real antique but it isent its a fake and you would pay loads of money for some crappy thing that isent even real so you would lose loads of money.
Check the water pump. If the thermostat is working properly then the next common problem would be a bad water pump.