89 Dodge van overheats, no water leak, replaced thermostat but still overheats.
this sounds more like a radiator problem, or possibly an electric fan, if there is on. Usually the water pump will lose the weep hole gasket on the bottom of the water pump and dump water when its running, but quits when you stop. A water pump bearing can start to sieze, you may notice temp fluctuating almost to hot, then drop back down. Take off the radiator cap when the vehicle is cold and start it up. let it idle until the thermostate opens. and watch the water in the radiator to see if it circulates at all as someone slowly raise the idle up to 2 thousand rpm, and rev the engine a few times, and see if the coolant momes across the radiator. It may be your thermostate is stuck partway, or the radiator is ready for a rebuild, they generally are good for about 20 years or so. I suggest using distilled or filtered water in your radiator if you replace it. There are many harmful chemicals in tap water, much more than people realize, and they can combine with chemicals in antifreeze and cause solder rotting electrolysis. By using distilled water, you minimize this risk and studies by major radiator companies have been proven to make radiators last a lot longer if a minimum amount of care is taken, like changing antifreeze every few years, and using distilled water as much as possible. I buy mine in the gallon jugs. and top off the overflow occasionally.
leave the cap off and start it. if it circulates then the water pump is still good. you say it overheats? flush out the radiator. if that van has a electric fan then make sure it is kicking on.
You probably need a new radiator, they become restricted and do not allow enough water to pass through to efficiently cool the engine.
A water pump shows signs of dripping through whats called a weep hole on the underside of the water pump.
um. yeah very good idea to replace it if you havent in a good while since you owned the vehicle. Oh and may as well do the timing belt or chain because u have to take it off to get to the water pump. also i would recommend a coolant flush to solve your over heating issues. If thats not the case.....check your heater core. symtoms of that are a leaky floorboard and smells of antifreeze coming from your vents as your heater is blowing.
