Water pump question?

[JustBob]

I checked the water pump and it seemed to be working, but when the engine reaches temperature and the thermostat opens, the water surges as if it is boiling over. Also, there is no heat from the floor vents (standard a/c system, not auto a/c). I do not have a temp gauge yet so I am using an infrared thermometer.

I checked and backflushed the system, heater core is clear, cannot find any blockages.


'88 Grand Marquis, stock engine...
I changed the following:

• radiator
• thermostat
• all heater hoses

Is there a valve on the heater core, or should it have flow at all times?
Maybe I just need confirmation that I should go ahead and replace the water pump. I found a cardone cast iron pump(not the severe duty) with the 3 7/8 impellar for 27.99....

[86VickyLX]

I checked the water pump and it seemed to be working, but when the engine reaches temperature and the thermostat opens, the water surges as if it is boiling over. Also, there is no heat from the floor vents (standard a/c system, not auto a/c). I do not have a temp gauge yet so I am using an infrared thermometer.

I checked and backflushed the system, heater core is clear, cannot find any blockages.


'88 Grand Marquis, stock engine...

I changed the following:

• radiator
• thermostat
• all heater hoses

Is there a valve on the heater core, or should it have flow at all times?
Maybe I just need confirmation that I should go ahead and replace the water pump. I found a cardone cast iron pump(not the severe duty) with the 3 7/8 impellar for 27.99....

Does heat come out anywhere else? If yes, the door is broken for the floor position.

And what do you mean the water surges?

[JustBob]

Does heat come out anywhere else? If yes, the door is broken for the floor position.

And what do you mean the water surges?

No heat from anywhere...

As the thermostat opens, the water level will fall and then surges out (it doesnt just rise and overflow) and eventually comes out rather forcefully as if it is overheating. The highest temperature at the thermostat I have seen when it does this is about 220 F...

[86VickyLX]

No heat from anywhere...

As the thermostat opens, the water level will fall and then surges out (it doesnt just rise and overflow) and eventually comes out rather forcefully as if it is overheating. The highest temperature at the thermostat I have seen when it does this is about 220 F...

Do the hoses going to and from the heatercore get hot?
If yes, there's an issue with the blend door, if no, then you have an air pocket.

I'd be willing to bet you have an air pocket. So do this, with the engine cool, fill the radiator to the brim. Start the engine, the level should go down. Fill it up again with it running. Turn the heater on high full blast. Hold the throttle open and add more coolant. Close the radiator and release the throttle, fill the reservoir and let the engine warm up. The hoses on the heater core and the air coming out of the vents should be hot or start to get hot. Rev the engine, the upper hose should start to close on itself. (this is normal since there is air in the system) You should notice that as you hold the throttle open, the hose starts to regain its shape, and once it is round again, it should be pressurized and hot to the touch.

Also, while you're worried about overheating, check out the fan. When the engine is hot, shut the engine off, the fan should stop spinning almost immediately after the engine stops turning. If it doesn't, the clutch is toast, get a new one.

[JustBob]

Do the hoses going to and from the heatercore get hot?
If yes, there's an issue with the blend door, if no, then you have an air pocket.

I'd be willing to bet you have an air pocket. So do this, with the engine cool, fill the radiator to the brim. Start the engine, the level should go down. Fill it up again with it running. Turn the heater on high full blast. Hold the throttle open and add more coolant. Close the radiator and release the throttle, fill the reservoir and let the engine warm up. The hoses on the heater core and the air coming out of the vents should be hot or start to get hot. Rev the engine, the upper hose should start to close on itself. (this is normal since there is air in the system) You should notice that as you hold the throttle open, the hose starts to regain its shape, and once it is round again, it should be pressurized and hot to the touch.

Also, while you're worried about overheating, check out the fan. When the engine is hot, shut the engine off, the fan should stop spinning almost immediately after the engine stops turning. If it doesn't, the clutch is toast, get a new one.

The heater hoses very slowly gets warm next to the engine and then slowly but progessively gets warmer as the engine heats up. When the engine reached 200 F the heater core inlet hose was at 125 F midway to the heater core. I did think about an air pocket, that is why I bled and filled the system at the heater core and the radiator.

I will refill the system in the morning, as it blew half of the water in the radiator out, and double check everything. I will also try your recommendations on filling the system. The cooling fan stops turning as soon as the engine is shut off.

If that fails, I will pull the heater hoses and check the actual flow coming from the pump, I should have already done that instead of thinking about it so much, lol.

Thanks,
Bob

[JustBob]

Do the hoses going to and from the heatercore get hot?
If yes, there's an issue with the blend door, if no, then you have an air pocket.

I'd be willing to bet you have an air pocket. So do this, with the engine cool, fill the radiator to the brim. Start the engine, the level should go down. Fill it up again with it running. Turn the heater on high full blast. Hold the throttle open and add more coolant. Close the radiator and release the throttle, fill the reservoir and let the engine warm up. The hoses on the heater core and the air coming out of the vents should be hot or start to get hot. Rev the engine, the upper hose should start to close on itself. (this is normal since there is air in the system) You should notice that as you hold the throttle open, the hose starts to regain its shape, and once it is round again, it should be pressurized and hot to the touch.

Also, while you're worried about overheating, check out the fan. When the engine is hot, shut the engine off, the fan should stop spinning almost immediately after the engine stops turning. If it doesn't, the clutch is toast, get a new one.

I was so worried about the water pump, I overlooked something...
I remembered after I had bled and refilled the system I had found a heater hose clamp that was loose, and that is where I got the air in the system.

First thing this morning after I got the battery recharged, I checked the water pump by attaching a long piece hose to the heater core line and it indeed had good flow. After that I remembered about the hose clamp... I checked the blend door and it is working right, and now I have heat coming out.

Thanks 86vicky.