Needing Some Heat Help

[TMyers]

2013 CTD
EVIC gauge shows the truck at 188 to 192 degrees when warm.
With the heat full on, dash (face) vents selected, when I turn the fan on high, I get a burst of Good Hot air from the vents.
After about 10 seconds, the air goes to lukewarm at best. If I turn the fan back off and wait about 30 seconds then turning it back on to high, I get the burst of Hot air again, then lukewarm.

I would greatly appreciate any advice.

 

[KCJackson1]

Do you get full/steady heat from the floor ducts and windshield defroster? If so, start by checking blend door operation. If you get the same spotty performance from the floor and defroster, probably start with the heater core.

 

[TMyers]

Do you get full/steady heat from the floor ducts and windshield defroster? If so, start by checking blend door operation. If you get the same spotty performance from the floor and defroster, probably start with the heater core.

I've got the hood up now looking at flushing the heater core. I didn't check to see if the floor and defrost had the same issues. Sense it's cooled some, should I reheat the motor and check or go forward with the flush?

 

[KCJackson1]

The flush shouldn't make anything worse. Finish that, then check all three vent levels - floor, dash, and defrost. If they're all working normally, then you've likely solved the problem (or at least remedied it for a while). If not, then the blend doors are probably next on your list. And you'll probably know during the flush if the core is bad and needs replacement.

 

[gsbrockman]

With an infrared thermometer, try shooting both hoses attached to the heater core.

 

[R.Taylor]

Is there a re-learn process for the servo controlled blend/air supply doors?

 

[TMyers]

Update: I HAVE HEAT!!!!!
I flushed the Heater Core with water hose and air.
I will add pictures later.

 

[TMyers]

I did the flush both directions, several times. After flushing, I poured distilled water into the hose until it filled the heater core then blew it out. I did this 3 or 4 times to rid the core of regular water.

If I were going to do it again, I'd buy new clamps. The squeeze clamps are junk.

I literally have to turn my heat down now.

 

[Cummins12V98]

That’s great!

How many miles are on your truck?

 

[TMyers]

That’s great!

How many miles are on your truck?

96k

 

[KCJackson1]

Glad it wasn't more complicated than that!

 

[Cummins12V98]

Seems odd with that mileage having an issue since the coolant is supposedly good for 10 year 150,000 miles. Thoughts anyone???

 

[TMyers]

Seems odd with that mileage having an issue since the coolant is supposedly good for 10 year 150,000 miles. Thoughts anyone???

First, I've owned the truck a little over two years. It's never heated good until yesterday. I wish that I would have tried to catch what was flushed out of it. I don't know if it was sludge or solids.

If I got all of the sediment out, the heater core doesn't have very much volume. It wouldn't take a lot to restrict it. After I flushed it, I blew the lines and core out then refilled them with distilled water from a gallon jug. Just eyeballing the jug, it didn't take a quart to fill the lines and the core.

My coolant looks great but I did just change out the turbo actuator and added 4 gallons of new (OAT) then. I wonder since the fins are so small in the core, if any flux or manufacturing debris in the system collects in it.

 

[Ozymandias]

Keep the spring loaded clamps, get pliers for it. They are the best to keep it sealed hot and cold.

 

[Cummins12V98]

TMeyers thanks for the reply.

Looking into the fill hole on mine the looks of the antifreeze in there never has given me the warm and fuzzy!

Maybe it was mentioned? Should the in and out lines each have the same temp under normal operating conditions lets say with the HVAC system "OFF" ?

 

[gsbrockman]

Seems odd with that mileage having an issue since the coolant is supposedly good for 10 year 150,000 miles. Thoughts anyone???

Perhaps the water pump or radiator Y-pipe was replaced......and the wrong coolant was installed (HOAT) then mixed with the existing OAT coolant.

 

[TMyers]

Perhaps the water pump or radiator Y-pipe was replaced......and the wrong coolant was installed (HOAT) then mixed with the existing OAT coolant.

I had the water pump recall done about a year and half ago. I didn't have good heat before it was changed. The "Y" pipe still has the plastic clamps so it's not been changed. But, I have thought that the wrong coolant could have been used to top off the system prior to me purchasing the truck.

 

[HPSimpson]

"IF" wrong coolant was installed you need to immediately drain and flush the current coolant (Hoat) and ( Oat) aren't compatible period will tend to turn to mush and clog your coolant system.

 

[sjacoboski]

I did the flush both directions, several times. After flushing, I poured distilled water into the hose until it filled the heater core then blew it out. I did this 3 or 4 times to rid the core of regular water.

If I were going to do it again, I'd buy new clamps. The squeeze clamps are junk.

I literally have to turn my heat down now.
View attachment 118246 View attachment 118247 View attachment 118248 View attachment 118249

Is your 3rd picture the heater core in or return line? I have to do the same thing since my water pump went. I was wondering if the plastic fitting was in or the return from the heater core? Obviously I would like to flow in reverse first

 

[JR]

The 3rd picture is of the supply line. It comes directly out of the head.