92 Ford E350 Water Pump?

[fleetw00d]

92 Ford E350 CHurch Van (doesn't get looked at until there is a problem). Now that the weather has cooled off (Ohio), the driver complains that the heat doesn't work. Drove it 40 miles to my house to work on it, the temperature gauge seemed to be in proper position, but as the driver said, no heat (barely warm up front). Rear heater pipes rusted out, I have cut them out and capped the lines. Radiator took 1 1/2 gallons. Started and ran without the radiator cap on, when the engine was to temperature according to the guage and touch (with cardboard over the radiator), the fluid in the top tank appeared stagnant, even when revving the engine. There were some bubbles and the clear water I put in eventually turned green. Still very little heat from the front heater. Assuming the thermostat was open, shouldn't I see flow across the top tank? If the thermostat were stuck closed, wouldn't I get A LOT of heat from the heater (assuming it's not plugged). Does all this tell me the water pump impeller is not turning with the pulley? Thanks!

[Mr T]

When water pumps fail, you usually see coolant dripping /running out of the weep holes near the pulley.

Does the heater blower work ok? Is there a water valve on the heater hose? (usually under the hood by the firewall). Does the heat diverter flapper (hooked to the heater control) operate? (You can often see it move looking into a floor air duct, or the recirculation inlet duct (if you have AC)

I would flush out the cooling system before doing anything. Especially with the rear line damage you mentioned. Are you sure you didnt open any loops by taking out the rear loop? Flushing may open up leaks that have been sealed shut by stuff moving in your coolant. Check the whole system for leaks after flushing.

IF you t-stat is stuck closed, you overheat. If it is stuck open, you dont heat up easily, or at all in some cases. (no heat from the heater either) A stuck closed stat shouldnt effect your heat too significantly.

[fleetw00d]

No coolant from the weep hole. I don't see a water valve for the heater, but the view under the hood isn't very good (until I remove air cleaner & such). Blower works OK. Flapper works OK. I cut off the rear pipes near the front, then short circuited them together with heater hose with a piece of dowel rod in the hose to block the flow. It doesn't overheat, but again, no apparent flow across the top of the radiator. Doesn't the heater supply come directly off the pump upstream of the t-stat so that if the t-stat is failed closed (and the water pump is pumping) you would get lots of heat but not see circulation through the radiator? I may just remove the lower hose and see if I can spin the water pump impeller relative to the pulley.

[removeb4flight]

I have a 1997 Ford E350 van. It had a similar problem. No control over the heat level. It seems that Ford built a defective heat blend box which then causes the motor to the heat blend flapper to fail. I got mine fixed for about $400, at an independant shop. They showed me the cause of the problem. Be sure that flapper is moving. I don't know if the 92 has the same design, but it's worth a try.

[fleetw00d]

Thanks. Heat blend door moves OK; it is directly controlled by a lever, not a motor. I am more concerned about the apparent lack of flow through the radiator.

[fleetw00d]

Verified that the water pump impeller turns with the shaft (stuck a wire in the discharge and tried to turn the pulley). Decided I had to go ahead a pull the heater core - after removing it (and tearing off the inlet and discharge pipes in the process) I could see that it was almost completely correded closed. Installed a new core, then a new radiator (new pressure cap made it obvious the radiator wouldn't hold pressure). Now I get 140 degree air from the heater. Thanks. See new posting on brakes.

[Mr T]

Great... You should hook the rear one back up now...

[fleetw00d]

The rear is going to have to stay capped off for now - new pipes are $200+ and I would probably have to pay someone else to install them, I couldn't get new ones in my '99 when they rusted out.