We have replaced the following;Radiator,fan relays,thermostat,temp.sensor,upper and lower hoses,radiator cap. We tested fuses,waterpump.the heater core seems to heat okay when it is not overheating.We have been told that the problem is more than likely air pockets??? How do you get the air pockets out??????? We have tried everything we could possibly try but we are not sure if we have done this correctly,we have tried bleeding the block and thermostat housing,what do we do next????
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
You may have air trapped in the cooling system. This will cause overheating. When you fill the system, there is a small brass air purge valve above the coolant pump and another on the thermostat housing. These need to be loosened and trapped air released when filling the cooling system.
a temp sensor only monitors what the engine temp is it will not cause the engine to overheat or run hot. check to make sure the rad cooling fan is working if not it could be a bad fan motor, temp sensor for the computer to turn on the fan or a fan relay. there are 2 temp sensors on motors. one is for the gage or light the other is to tell the computer to turn on the cooling fan.
Check the cooling fan, thermostat or radiator. I'd start with the basics and check to make sure cooling fans kick on. If they do, remove the thermostat and recheck. If it still fails and bottom and lower radiator hoses are hot then you have a plugged radiator
suggest that you rent a pressure tester from auto zone or advance auto and preform a pressure test on your cooling system. follow the instructions on the test of pressure to your cooling system,also check for coolant leaks onto the ground from radiator area. may be bad water pump,broken hose,heater hose,upper radiator,lower radiator,or a bad radiator itself. a simple pressure tester will reveal the coolant leak. but make sure to follow the instructions with the pressure tester,as you can damage your coolant system otherwise. thank you for choosing fixya.com
does the upper and lower hoses seem to be the same temp when car begins to overheat? ore the radiator cooling fans coming on before the car overheats? did you pressure test the cooling system and radiator cap? also may want to remove the lower hose and flush the radiator. is the check engine light on and does it run bad?
First check if you have any leaks in the cooling system , then check if level is correct(radiator and expansion tank , check level when car is cold , never open radiator when it's hot).
Then verify operation of radiator fan , if it's electrical fan it should comes on when temp. goes over normal,
if it's a clutch fan- it should pick up a speed and be more loud. If fan is not on and engine is starting overheating , check upper and lower radiator hoses.
If upper hose hot and lower hose cold or warm then you might have stuck close or prtially closed thermostat , difference between lower and upper hoses when t/stat works ok is about 10-15 degrees,
not really noticeable for hand.So if you don't feel a lot of difference between hoses temp. , and fan is not on , check fan or fan clutch itself.
If lower hose cold , replace thermostat and purge system.
If everything above is working properly , and it's still overheating , you may have bad water pump or head gasket.
you have 4 water lines, they are 2 radiator hoses (top and bottom) the bottom one runs from the lower part of the radiator to the water pump, the top radiator hose runs from the upper part of the radiator to the thermostat housing
2 heater hoses, they go from the water pump to the firewall.
if you know which one has a hole then you should take the van to a parts store (if you can safely drive it that far) and show them, they can get the right one for you... and sometimes you can talk someone into putting it on for you.
as for the fluctuating gauges you probably need new sending units for the temp gauge and fuel gauge
many things could cause the overheating. broken water pump impeller, stuck thermostat, clogged radiator, inoperative cooling fan on the radiator.
i would first check to see if the cooling fan on the radiator is working. when it reaches operating temp (or surpasses it in your case), see if the fan attached to the radiator kicks on. if its not on, then either the fan has failed or the temp relay to kick on the fan has failed. also, make sure the connector is plugged in.
after its at operating temp, turn off the car and feel the radiator. if you feel cool spots, then it is clogged and needs replacing.
wile under the hood and car is off, feel the upper & lower radiator hoses. if one is hot and the other is cool, then either the water pump (actually the impeller on it) has failed and is not circulating coolant through the radiator. a common problem in this model.
but it could also be the thermostat. if failed, it would not allow coolant to flow & circulate.
hopefull one of the above items is the problem. good luck.
To locate the thermostat follow the upper radiator hose from the radiator to the engine it will be at the end of the hose. Also if you have an electric secondary fan make sure the sensor that controls it is working or the engine will over heat.