No heat !

TUDDA · Post by **TUDDA** » Sun Oct 19, 2008 8:10 am

Only getting cold air blown into the cab when turning the heat on. Could it be as simple as changing the thermostat to get that warm comfy felling again?

Post by **HenryJ** » Sun Oct 19, 2008 9:13 am

It might be, but check the coolant level first. While you are there check the condition of the coolant. Dexcool is known to gel and plug up the heater core. That is a possibility too.

There are good threads on how to flush and change the coolant. That would be a good idea if it has been more than two years since it has been done.

If that is all good read the stickied thread on the transfercase switch. Checking for ATF in the system would be my next concern.

F9K9 · Post by **F9K9** » Mon Oct 20, 2008 12:41 am

HenryJ wrote:It might be, but check the coolant level first..............

X2

TUDDA · Post by **TUDDA** » Tue Nov 04, 2008 2:19 pm

Changed thermostat, still getting cold air

killian96ss · Post by **killian96ss** » Tue Nov 04, 2008 2:35 pm

TUDDA wrote:Changed thermostat, still getting cold air

Was the coolant level normal?

If the coolant level is normal then you most likely have a plugged heater core which is caused by Dex-Cool and air contamination in the cooling system.

You could try unhooking both heater hoses and flush the heater core with a garden hose, but if that doesn't work then you will need a new heater core.

It would also be be a good idea to switch to the standard "green" coolant and replace your radiator cap.

Steve

TUDDA · Post by **TUDDA** » Tue Nov 04, 2008 7:24 pm

Thanks, Steve

TUDDA · Post by **TUDDA** » Tue Nov 11, 2008 8:27 am

Bought 2 lengths of 6' hose the same diameter as the hoses on the heater core,and ran them off the front of the truck. Ran water from garden hose through both lengths of hose. Some brown GUNK ran through the lines then cleared. Filled radiator and reserve with fresh dex, then started truck with fingers crossed. Put a thermometer in the vent and temp reached 123 degrees!

Took it for a spin and temp was up to 145 degrees. Hopefully that will get me through the winter. THANKS for all the help.

Post by **HenryJ** » Tue Nov 11, 2008 8:58 am

Keep an eye on that Dex. It doesn't like contaminants. Distilled water is a good choice for mixing. Hard water can be seen by Dex as a contaminant. Flushing the whole system and draining everything, including the engine block, is the safe bet.

You might get lucky, but I would guess that the rest of the system still hides some of the brown gunk you flushed from the heater core.