major problem, need help quick!

[ca1a73]

Well, I finally finished the heater upgrade in my bronco! Took a while because my electrical was screwed up, but got it all figured out.
I start the truck up to test the heater. As the temperature rises, Im still getting no heat, only cold air. Next thing i know the truck is overheating, up over 200 . I shut her down. Both radiator hoses(upper and lower are ice cold). What the hell is going on? Did i put the hoses on backwards in the heater? Would that make sense? or is this something bigger?

 

[big daddy walt]

Is your radiator full? Not enough water will make your engine overheat and not produce heat.

 

[ca1a73]

I drained a little before i took the hoses off for the heater upgrade. I added water to the top of the radiator before i started it up tonight. obviously it isn't getting to the heater core, because i had no heat. just cold air. but my engine was overheating. Could the valve be shutoff? I don't even know if i have one. Besides, even if it was, it shouldn't be overheating, right?

 

[Case]

did your bronc have any probs before you worked on your heater?
is the thermostat good. sounds like it might not be opening, but that would stop coolant from going to the heater core.
any more info you could give us?
you may want to check the coolant level again. there might be an air pocket.

 

[Flash69]

The valve for the heater is in one of your heater hoses. Mine is kinda on top of the passenger side valve cover. It sounds like your thermostat aint opening. And as was said before make sure you have plenty of coolant. Even with the heater valve closed it still shouldnt overheat.

 

[ca1a73]

I never had an overheating problem before the heater upgrade. I just went out and checked my coolant. its full.!!! motor is heating up, but the heater core isn't. Still blowing cold air. Is it possible I installed the feed and return lines bakwards on the heating core? Would that cause it? Not sure how those heater cores work.

 

[ca1a73]

maybe i have an air bubble. I did let some out of the petcock before i took off the heater hoses. This sucks! How do i chech for air in the lines?

 

[Oldtimer]

You said your electrical was all messed up?
Temperature gage is electrical??
Maybe you engine is not over heating.
The water pickup for the heater is at the top of the intake manifold. The fitting usually reaches 1/2" to 3/4" down into the intake. If there is air in the system, & the fitting does not reach water, the heater core may not get any.
Summer is just around the corner, wait till next year?

 

[mtkawboy]

Man you have a lot of problems. It doesnt matter which way the hoses are on as far as heating. Hooking them up backwards just makes a lot more heat in the cab in the summer. Did you run it long enough for the thermostat to open? The bypass hose should make a little heat until the thermostat opens. If it shows a whole lot of heat on the gauge but the top hose is still cold then the thermostat isnt opening

 

[ca1a73]

I sure do have many problems, lol... most i creat on my own unfortunatley. Yeah, the top hose was ice cold. Should i let it warm up more and hopefully it will open? I just replaced that thermostat last summer....grrrrr. My luck. Thanks for the help guys. Any more ideas or comkments are welcome.

 

[ca1a73]

I just tried running it again. Same thing. And no change in the motor rev as the thermostat opens. Upper hose is ice cold. Looks to be the thermostat. What would cause this? Anything else i should try before replacing the thermostat again.!

 

[2badrotties]

Well here is a stupid question... did you by any chance stick a paper towel or something in the hoses to keep antifreeze leaking out ? I know it sounds like a dumb question but shi# happens. I put a carb on my racecar with a shop rag stuck in the intake once :-[

 

[ca1a73]

Not that i can remember 2bad...lol. Its just strange that all of a sudden imy thermostat isn't working. When i shut the motor off, sounded like it was boiling at the thermostat housing, and was very presurized. Im guessing thats because it didn't open. Good thing this isn't my daily driver. It looks as though my heater control valve on the intake is unhooked. I see the end of the wire where it goes through the firewall. It might have never been hooked up. I can't even find the bypass valve. I can follow the hoses until they get to the metal hoses, running under the intake, to the waterpump housing but no valve.

 

[Flash69]

Not that i can remember 2bad...lol. Its just strange that all of a sudden imy thermostat isn't working. When i shut the motor off, sounded like it was boiling at the thermostat housing, and was very presurized. Im guessing thats because it didn't open. Good thing this isn't my daily driver. It looks as though my heater control valve on the intake is unhooked. I see the end of the wire where it goes through the firewall. It might have never been hooked up. I can't even find the bypass valve. I can follow the hoses until they get to the metal hoses, running under the intake, to the waterpump housing but no valve.

You can open and close your heater valve by hand if it aint hooked up. straight toward the front is closed and toward the back or straight up is open. Sorry i just read your post better. I see that you said the valve aint there.

 

[2badrotties]

If you have NO heater valve in either of your hoses you WILL have heat no matter what. Without the valve there is nothing to keep hot water from the heater core. Try letting it run with no radiator cap. ?:?

 

[ca1a73]

that probably explains why my feet melt in the summer time...lol. No bypass valve. Is that common in a 5.0 swap? What should happen with tha radiator cap off?

 

[big daddy walt]

sounds like the thermostat. does it get hot real quick? (water pump)

 

[ca1a73]

It runs normal until about 160degrees, then climbs pretty fast from there. Its an 87 5.0 with serpentine setup. So water pump should be going, correct?

 

[ca1a73]

I took the hoses off from the heater core. fluid drained from both, so the coolant made it through the heater core, only its ice cold.

 

[dpmerrill]

Time to start ruling things out. If your fan belt is hooked up, your thermostat is installed pointing the right direction, and you didn't leave anything blocking the radiator hose, I would start by checking the thermostat.

It's a pain, but I would pull the thermostat out. Reinstall the thermostat housing without the thermostat in it, and run the engine with the radiator cap off. You should see water flowing through the radiator.

If water flows, you have a bad thermostat, or it was installed backwards. If there is no flow, you have water pump issues, or something is blocking your passages.