my coolant system is not always flowing to keep my water hot! I think the radiator and the heat exchangers are keeping my coolant to cool! I also think the radiater fan is always turning, does it have a cluch that should only engage when hot or should it always spin? I have replaced the thermostat to a 195, and a new water pump!
Whether you have a thermal or viscous type clutch the fan should always be spinning. You will need to check a couple of things if you think you are not circulating the coolant. First make sure there is no air in the coolant lines. Especially after changing a water pump you will need to purge the air from the system. Most often air gets trapped at the heater core. Bleed the outlet side of the heater core until bubbles disappear. Next would be to check the radiator cap for the proper pressure. This is such an overlooked factor. If you dont have a tester you can rent one from an auto parts store (make sure you get the attatchment for cap). Or a local mechanic should be able to do it for free. You have a better chance of getting it done free if you walk in with the cap in your hand. Finally, check for any engine vacuum leaks. If there is a vacuum leak the vacuum control module that opens and closes for coolant flow in the truckmount will not work properly. Its probably something simple you are overlooking. Good Luck!
Excellent advice fron Ara. My old CDS produced MUCH hotter water after taking care of vacuum leaks. It's getting a new radiator and fan belt today. Been raining like crazy for a couple of days.
I think I'm haveing a problem with the waterflow through the heat exchangers! I warmed up the van and then turned the key on and felt the heat exchangers and it took 8-10 min to get the end of the second heat exchanger fairly hot! the temp on the input exchanger is mutch hotter! any help on the process for checking components would be greatley appriciated, not sure where to start!
Did you check everything I stated above? Like the vacuum control module? Engine vacuum leaks? Or you can try hooking up a gargen hose to the HX and see if there is a restriction somewhere.
The inlet for the first heat exchanger is very hot and at the end of the second HX, the oulet back to the engine it is cold when the van is level and I'm cleaning. I drove the van home and the oulet is hot after going up a few hills! I called Jondon today and they said I probibley had a air pocket in the exchanger! I parked it on a hill and removed the radiator cap to see if I could pass the air bubble and after 15 min I drove the van back home and the temps on the ends of all the HX were within 5 deg., so I thought I had it fixed! I went to clean tonight and same problem! can't get the coolant to flow through the HX on level ground. I asked jondon about the vacuume and he said on the older 4.7 the vacuume didn't effect anything, mayby with the newer units with the SALSA, not sure if he is wrong, can you confirm!
I dont know who you talked to at JonDon but "engine vacuum" plays a major roll in controlling the module that opens and closes the valve for flow. Maybe you did not specify engine vacuum to the guy.
I tried searching the internet for a controle module and found nothing for my 97 Dodge 3500! I have a Thermostat that opens and a waterpump! where is the controle module!
It should be before the heater core for the cab. There is a valve that controls coolant flow right there. You should observe those controls.
My heater core is bypased, I think the coolant hose used for the heater core is now used for the inlet coolant for the Heat exchangers! I will look for vacuume leaks tomorrow. I know for sure the Heat echangers are not pluged! I flushed some water though them today and they seem to flow great! I also replaced one of the lines with a new hose to remove the coolant flow flap to stop the flow of the coolant through the exchangers! It still gets very hot at the exchangers when parked on a hill with the nose of the van up in the air! I will check my heat after I let it cool down! I do know if what I did today doesn't work my problem is coolant flow out of the engine or still a small air pocket in the heat exchangers!
Seems to be working fine after flushing out the Heat exchangers! their was some particles in their that must have been blocking the water flow! when I flushed it didn't seem to be restricted!
