another cooling system problem

97 astro van overheats on the freeway when i go about 65mph. the temp is usually around 190, 200 when i first start driving. after about ten miles or so it then jumps to midway on the scale and remains there until i get off the freeway and do normal driving 40 to 50mph on surface streets. it then runs about 190, 200 again. replaced the water pump at about 100,000 miles. the car now has 185,000 miles on it. the heater does not work. any clues??? thanks edsel.

AS far as the temps going up while running at highway speeds and being reasonable at lower speeds : that indicates a collapsing lower radiator hose to me.

As far as no heat goes, no heat at any time?

no heat at anytime. in fact i checked the hoses to the heater and they do not get even warm. i will probably open the heater hoses to see if they are blocked with coolant sludge. ok the lower radiator hose is collapsing? then i need to replace it? when i get home from work thursday. thanks for the advice. edsel...

could be air locked, bad water pump plugged heated core

No heat sometimes means head gasket gone bad. If you are missing antifreeze and no leak in seen then head gasket might be the culprit. As for overheating on the highway lots of people never check between the radiator and the a/c radiator. if that is the case after you get the radiator cleaned put a screen in front of the front radiator. you can get screen at any hardware store. good luck :)

ok looks like i had air in the system. ran the engine with the rad cap off and topped it off. drove car to work twice past week, about 70 miles each way no problem. however the coolant level keeps going down, about half a pint to a pint over the week. no visible leaks. i do not have any heat either and the blower fan is not working. i made another post regarding the blower which works if i put power directly to it otherwise no go. thanks and any further clues edsel...

smell your exhaust if it is sweet then your burning coolant. or another sign is if it is white after being warmed up, but you will usually smell burning coolant.

Another thing to check is your freeze plugs. It could be leaking there. Also try filling it up with water drive it just a little bit then pull over and check your water pump for leaks while vehicle is still running.