No heat in cab only luke warm and some other issues

[kdub0013]

No heat in cab only luke warm and some other stuff
Well I just got my 93 f250 7.3l IDI and I am going through everything now. I noticed that my temp gauge at operating temp is on the "n" in normal but all my hoses are hot so I'm thinking tstat? Got a new one from ford today and then I was thinking heater core but there was nothing leaking on my floorboard but again I have no heat in the cab, Any thoughts? Blend door and where is that?

Next is fuel additive what are you all running?

What are you all running for coolant with sca's and do I need to flush it or just drain and change?

Lastly any other tips or tricks or a good website I could read up on, yes I know how to search and google but I want to hear from those with experience on these rigs, all I know is toyotas.

Thanks!

 

[NJGearhead666]

the Ford factory gauges are glorified idiot lights, get yourself some good aftermarket gauges.

 

[88beast]

n to l is mormal lol it will hit hot after you see smoke.
i use lucas it works great and has a noticible power gain
to get to the blend door pull the heater core look inside to the left its a big plastic flap.
the blend door could be stuck or jammed up i had a rat nest in mine when i bought it.
the vacume lines control the blend door if youre not getting enough vaccume this could cause the door to not move when you switch from vents to defrost do you hear the door moving? run the truck and then shut her off and try that.
also the heater core i dought if both hoses are hot one will be much cooler if the core is not working. if theres flow it will make heat.
also when you got the core out check the heater box itself mine aquired a huge hole on the bottom at one point. hope this helps some

 

[kdub0013]

Hey thanks for the replies guys. I am all over the pirate4x4 forum so I am not used to the generous responses to questions that to most on here are probably simple ones, anyways I will check the blend door and good to know on the temp. I figured as long as it's not hot I am good. I will post up when I figure it out.

 

[subway]

its more likely what is already mentioned but i steadily loose my heat when my condensor freezes up. the ac runs on any position other than the front vents, and on mine freezes solid in the colder weather cutting my airflow and heat.

i am guessing my system is overcharged to do this to me.

 

[hesutton]

Any idea of the condition of the heater core? If it is old and full of crud, it may not be flowing enough coolant to heat the cab. If you are not getting a change in the location of the air flow when switching from defrost to floor to vent, then your distribution door may be screwed up as Tom suggested above.

As for the coolant. It's best to flush and replace, but honestly, a full drain and refill it just fine. But, you need to try and get all the old coolant out as best as you can. Be sure to pull the block drains in addition to just draining the radiator.

You'll get lots of answers on coolant and SCA suggestions. But, these motors were designed to use good old ethylene glycol (green) coolant. Be sure to use only distilled water when you mix your coolant. Otherwise, minerals disolved in tap water will precipatate out of solution and form deposits all over the cooling system (rad, oil cooler, heater core,.....). I use DCA-4 from a Fleetguard precharged coolant filter. But, there are many other options.

Fuel additive, Power Service. I double dose each fill up, grey bottle in the summer, and white bottle in the winter.

Heath

 

[franklin2]

When you say "your hoses are hot" does that mean both heater core hoses? If both are hot, it sounds like you have a airflow problem over the core. If one is hot and one is cold, you have a coolant flow problem through the core.

 

[bayou]

marvel mystery oil is what i run for fuel additive.

as far as the heater goes, i generaly just replace the core and clean everthing when ever i have problems (almost never) but i dont like to do things twice, so take that for what you will

 

[kdub0013]

its more likely what is already mentioned but i steadily loose my heat when my condensor freezes up. the ac runs on any position other than the front vents, and on mine freezes solid in the colder weather cutting my airflow and heat.

i am guessing my system is overcharged to do this to me.

Yeah I am not sure on that, I know my A/C works great, but that doesn't help me now.

Any idea of the condition of the heater core? If it is old and full of crud, it may not be flowing enough coolant to heat the cab. If you are not getting a change in the location of the air flow when switching from defrost to floor to vent, then your distribution door may be screwed up as Tom suggested above.

As for the coolant. It's best to flush and replace, but honestly, a full drain and refill it just fine. But, you need to try and get all the old coolant out as best as you can. Be sure to pull the block drains in addition to just draining the radiator.

You'll get lots of answers on coolant and SCA suggestions. But, these motors were designed to use good old ethylene glycol (green) coolant. Be sure to use only distilled water when you mix your coolant. Otherwise, minerals disolved in tap water will precipatate out of solution and form deposits all over the cooling system (rad, oil cooler, heater core,.....). I use DCA-4 from a Fleetguard precharged coolant filter. But, there are many other options.

Fuel additive, Power Service. I double dose each fill up, grey bottle in the summer, and white bottle in the winter.

Heath

Not sure on the heater core, I know the PO said he never did anything with it and thought the heat worked fine but I am thinking the blend door might be the culprit, but I am going to go ahead and replace the thermostat too.

When you say "your hoses are hot" does that mean both heater core hoses? If both are hot, it sounds like you have a airflow problem over the core. If one is hot and one is cold, you have a coolant flow problem through the core.

Yep both heater hoses are hot, I will double check again but I am pretty sure that was it. So then if thats the case then I know the problem is under my dash.

marvel mystery oil is what i run for fuel additive.

as far as the heater goes, i generaly just replace the core and clean everthing when ever i have problems (almost never) but i dont like to do things twice, so take that for what you will

Thanks, I have heard marvel and lucas the most from people so I will check that out.

 

[OLDBULL8]

Check your vacuum motor for the fresh air door under the hood passenger side on top of the heater box.

 

[88beast]

tstat is nice to do as matience but wont help if both hoses are hot. disconnect the ac clutch plug itll take 5 sec should be the only plug on the ac compressor. that will tell you if the ac is over doing it.

 

[86.9]

I would pull your blower motor and see how the core looks. It may be plugged up and no air getting through. I clean the one on my 86 yearly. All manor of leaves and such are in there, but never to the level where no air gets through.

Jeff

 

[kdub0013]

Is the blower motor in the cab or the engine compartment?

 

[88beast]

engine pass side firewall on a big platic box you have a round metal motor