No heat, I've done everything

[curleywon]

I have no heat front or rear. Today I back flushed the entire cooling system with the kit which I installed in 2013 when I replaced the front heater core and radiator. I saw some rusted metal coming out but not enough to indicate a major blockage. I cut a hole behind the glove box to insure that the blend door is functioning properly. After filling the system, I still have no heat. Neither of the hoses going to the core are even warm and neither is the core itself when I touch it from the inside through the hole that I cut. I replaced the thermostat also. What am I missing? I also used a shop vac to blow as much water out of the system as possible before refilling. It only took 3 quarts to fill. I need help. I need heat.

 

[Russell Lewis]

Get ones of these

OEMTOOLS 24506 Cooling System Back Flush Tool

Or similar.

There is a block on the heater core. You can flush then back flush if there is no heat on inlet then there is a block not allowing water to pass threw the core

Do both hoes get warm top and bottom of your radiator hoses showing Coolent circulating in radiator ?

 

[curleywon]

Neither of the hoses going to the heater core get warm. I have this installed already.
https://www.walmart.com/ip/Prestone...35&wl11=local&wl12=16817507&wl13=4697&veh=sem

 

[98eb5.4]

engine temps normal? did u have heat at any point?

 

[curleywon]

engine temps normal? did u have heat at any point?

Engine temperature is normal. Truck was overheating at idle until I changed the thermostat. Has good heat front and rear last winter and into the spring on a few chilly days. No white smoke or antifreeze smell from the exhaust to indicate a blown head gasket. I can't get the quick connects off to do a direct heater core flush.

 

[98eb5.4]

should be able to flush the core just cutting the lines ~ 5-6" back?

u can also buy/rent/borrow the special tool but i found that a pia,

saw a good u tube vid showing back-flushing that seemed the better way to go

think i read where a worn water pump wasn't pumping enuff to get heat but otherwise was ok

 

[Russell Lewis]

Might need a water pump.

Parts places rent “ fan tool “
I used 1 1/2 wrench and the belt to hold tight. In a pinch quick fix. Check amazon with a few brands compare to rock auto for price winner is the cheapest.

 

[muskytom]

I have the same problem as curleywon - little to no heat front or rear and engine temp gauge normal/rises to and stays at the same position once warmed up. No overheat problem summer or winter. Was better last winter when I had a cooling system flush, but when temp got into low 20's and below, I started to notice it. At near and below zero, had to wear coveralls when -1 degrees driving from Chicago to Green Bay last week! Thermostat OK, coolant level OK, but heater core leak recently and "patched" with stop leak successfully. No change in heat but stopped the leak. Duct controls working OK. Any thoughts about heater control valve (can't seem to locate)?

At my wit's end. A friend mentioned to me that when he was a mechanic back in the early `70's, he encountered a no heat problem on a V-8 and referred to it as an "air-block" problem: air in the cooling system (but doesn't recall how he resolved it.)

Any ideas Group?

 

[Adieu]

I have the same problem as curleywon - little to no heat front or rear and engine temp gauge normal/rises to and stays at the same position once warmed up. No overheat problem summer or winter. Was better last winter when I had a cooling system flush, but when temp got into low 20's and below, I started to notice it. At near and below zero, had to wear coveralls when -1 degrees driving from Chicago to Green Bay last week! Thermostat OK, coolant level OK, but heater core leak recently and "patched" with stop leak successfully. No change in heat but stopped the leak. Duct controls working OK. Any thoughts about heater control valve (can't seem to locate)?

At my wit's end. A friend mentioned to me that when he was a mechanic back in the early `70's, he encountered a no heat problem on a V-8 and referred to it as an "air-block" problem: air in the cooling system (but doesn't recall how he resolved it.)

Any ideas Group?

Yeah you have idle the engine with the radiator cap off for a while, multiple times, and top off the coolant.

You can have several liters' worth of air bubbles.

Also....are you sure your temperature control isn't messed up? I mean the dials/buttons themselves

 

[muskytom]

The level in the fill bucket/overflow rises and lowers between hot & cold fill lines appropriately. I did have to add coolant, but don't recall if the engine was running - good point; I'll try that again.

Controls work fine: vent controls, fan speed and temperature runs the whole range from hot to cold - I feel it. Tried that almost immediately to rule out any binding or vacuum problems.

 

[1955moose]

The fact that you stated the hose going up to the heater core is cold, tells me your problem is a blockage before the core. Easy way to check water pump is pull lower hose crank over engine add water to radiator or expansion tank, water should surge out steadily. Be sure your hoses to heater core aren't reversed. The fact that it's not running warm, leads also to double check your blender doors at heater plenum. If you have a coolant air bubble, again it should affect proper running temp. Most readers here find a door not functioning or some sort of vacuum hose cut/ broke. Keep us posted. Moose.

Sent from my N9131 using Tapatalk

 

[muskytom]

Thanks for the ideas. I saw water pump mentioned in a previous post on the subject. But engine isn't overheating.

As for blend doors and vacuum hoses, we're talking about behind the dash, right? I would think they're working, as I can swing the temp from one extreme to the other and I do feel the cold. and only a trickle of warm air. Have to check the hoses as you mentioned. Thanks again.

 

[1955moose]

You can't assume the doors are opening and closing, you need to see it. The hoses coming off engine to and from heater core need to carry warm coolant. You need to pull hoses coming off motor to see where your blockage is. If your block is not grounded with the appropriate cables, you'll build up corrosion on your intake manifold, and all small passages. Happened to a friend of mine. His problem was overheating in hot weather. As stated earlier you need to know your flowing. It's possible your not overheating due to the cold weather.

Sent from my N9131 using Tapatalk

 

[muskytom]

Good points - I'll check and certainly let the group know what I find. Sidebar - never overheated in any of the past summers. Thanks again!

 

[98eb5.4]

Thanks for the ideas. I saw water pump mentioned in a previous post on the subject. But engine isn't overheating.

water pump may be weak, in that engine temps are normal but not much happens at the heater core

 

[Petesexpy]

I've heard that these trucks do not overheat even with a minimum amount of water coming out of the water pump. Check if there is any pressure in any water hoses with truck running.

 

[curleywon]

Update: Found two coolant leaks, one around the thermostat housing and at the quick connect (which was broken but still connected) leading to the rear system. I was losing a gallon every 10 days. installed another new thermostat and gasket and spliced the hose with new quick connect. Neither heater core hoses ever feels hot even after driving it. Inside temperature reads 58 degrees. Still haven't done a direct core flush. Thinking of bypassing the rear system altogether after front core flush.

 

[98eb5.4]

you can absolutely have normal engine temps & zero heat from the heater, running low on coolant

 

[curleywon]

The fact that you stated the hose going up to the heater core is cold, tells me your problem is a blockage before the core. Easy way to check water pump is pull lower hose crank over engine add water to radiator or expansion tank, water should surge out steadily. Be sure your hoses to heater core aren't reversed. The fact that it's not running warm, leads also to double check your blender doors at heater plenum. If you have a coolant air bubble, again it should affect proper running temp. Most readers here find a door not functioning or some sort of vacuum hose cut/ broke. Keep us posted. Moose.

Sent from my N9131 using Tapatalk

My blend door is working. I cut into the panel to verify.

 

[hammerg26]

Going to watch this one. I have very poor heat as well. Have not tried the back flush yet - looked at it, but not sure which hoses - rather not jack something up.


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