Heater problems on 01 7.3

[jsexton]

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I have a 2001 f250 7.3lt 4x4 and I cannot haul my kids because my heater has stopped working. I have replaced the radiator, waterpump, thermastat 3 times(latest one from ford for $50!), flushed system, blew out the heater core, put a vacuum pump off of my dad 350 on it, and it still will not heat. Well, it will heat now when rpm is over 1500 or while driving, but if i stop and let the truck idle the vents just blow cold air. Sometimes you still loose heat while driviing. I will appreciate any help im over my head and this is my first diesel!
Oh yeah, if i lock the hubs in it goes from vent to defrost! Is there a sensor or something that i could be overlooking? thanks for any help!

[dmd]

Locking hubs issue is just a vacuum leak at the hubs, common problem.

The heat problem is the interesting one, does the heater box behind the glove box get
warm? That would say if the heat is reaching the core. Wonder if someone
installed a valve in the heater line, but that wouldn't explain how heat works when
over 1500 rpm...

[Austin G]

Get your kids some coats. lol

[thatguy2010]

Check the connection at the heater box, mine did this same thing. The bumpy ride caused it to come loose. Hope it helps, otherwise it looks like you may be buying more jackets.

[jsexton]

I will check the heater box, but we have found that it will continue to blow hot as long as you keep the fan speed on low. If you turn the fan to high and let the truck set on idle it gets cold very cold! I loved the coat idea, but my wife didnt find it funny! LOL!! I have been told that i could have a partially block heater core and that would cause my problem. Does anyone know if there is a sensor that would stop the flow because when it quits heater the top radiator hose gets cold as well?

[jsexton]

Thanks for all the help guys! I replaced the heater core and that seems to have fixed the problem with my heat! Now i took it to the ford dealer for 2 recalls and the y called me and said that i needed a front hub assembly and i had an oil leak from my icp sensor. They want 250 for the icp sensor and 700 for the front hub assembly! I found them both on ebay the hub for 90 and the sensor for 75. Has anyone had luck with getting parts off of ebay?

[jsexton]

Well, new problem! ALOT of white smoke at start up. Goes away after i drive it down the road! I have read a lot of threads and say all kinds of things can cause this from water in the fuel to blow by of fuel! Any ideas!

[Gene]

Originally Posted by jsexton

Thanks for all the help guys! I replaced the heater core and that seems to have fixed the problem with my heat! Now i took it to the ford dealer for 2 recalls and the y called me and said that i needed a front hub assembly and i had an oil leak from my icp sensor. They want 250 for the icp sensor and 700 for the front hub assembly! I found them both on ebay the hub for 90 and the sensor for 75. Has anyone had luck with getting parts off of ebay?

I would do the ebay ICP. Or just change the o-ring on it.

For the hubs, I would change over to manual-locking hubs. While you will have to get out to set them, they will actually last longer and cost less.

Originally Posted by jsexton

Well, new problem! ALOT of white smoke at start up. Goes away after i drive it down the road! I have read a lot of threads and say all kinds of things can cause this from water in the fuel to blow by of fuel! Any ideas!

Cold weather can cause it, too. I don't know if the ICP could cause it, but since the dealer already said it need to be replaced.....

[jsexton]

Ok i put some more fuel additive and the white wmoke disapeared, must have been water in my fuel. I am back to the same problem with my heat! At idle it will not blow heat, when you drive down the road it heats fine until you pull up to a long red light and then you loose heat again until you start moving again. I have now changed the radiator, thermostat, water was changed recently and we took it off and inspected it(everything is tight and the vanes looked new), and we changed the heater core!!! Any other ideas that you guys have would be a great help!