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birchit

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I flushed the whole coolling system, when the big circulation was active - the thermostate was open. And the heating was on maximum. Is that correct or did I forgot something important. It seems so, because you asked in this way OLYELR. ;)
 
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birchit

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This may be viewed as semantics but, there is a considerable difference between flushing & backflushing.

Do you understand the difference?

Sometimes a backflushing activity requires a repeated effort or chemical support.



The reason members keep saying it's a heater core blockage is because they've seen this, many times before. And from those who have already backflushed.



If you use a laser guided temperature gauge, try measuring the temperature difference between the driver and passenger side HVAC vents.

Also, the DTC code you are referencing is not always indicative of blend door related fault.


Update:
I reread your first post and you mentioned "flushed cooling system ".

Is this what you're considering as 'backflushing the heater core'?

Please describe the method used including duration, connection points, flow direction and resulting material in outflow.

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Please explain the difference of flushing & backflusing, thanks!
The temperature difference from the driver to passender side is zero. It is equal. I doesn't matter which heater setup I use, everyhting works instead of the hot air.
Flushing: I warmed the engine up so the big circulation loop will work during the open thermostate and the heating was fully open. I put the system under pressure and flushed it after it. At the end I flushed only with water by the garden hose. That's it. The outflow was clean and no dirt in there. But what I forgot to say is that I used the PowerWagon as service vehicle at the Rally Breslau 2022 - biggest Offroad Rally in Europe. So could that might cause the problem of a blocked heater core surface with brutal dust?

Thanks for your support!
 

GTyankee

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back flushing HVAC heater core Dodge Ram, this truck is several years old than yours, Generation 3, but you get the general idea


This Ram is a 4th Generation, should be the same as yours, EXCEPT your Ram uses OAT coolant

 

RamDiver

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Please explain the difference of flushing & backflusing, thanks!
The temperature difference from the driver to passender side is zero. It is equal. I doesn't matter which heater setup I use, everyhting works instead of the hot air.
Flushing: I warmed the engine up so the big circulation loop will work during the open thermostate and the heating was fully open. I put the system under pressure and flushed it after it. At the end I flushed only with water by the garden hose. That's it. The outflow was clean and no dirt in there. But what I forgot to say is that I used the PowerWagon as service vehicle at the Rally Breslau 2022 - biggest Offroad Rally in Europe. So could that might cause the problem of a blocked heater core surface with brutal dust?

Thanks for your support!

The difference is simply the direction of flow.

You will be required to identify which hose at the firewall is on the inlet side versus the outlet side of the heater core.

If you have a laser-guided temperature probe, measure both hoses after warming the engine and record the temperatures of both for later in the process.

You might record a set of deltas with the HVAC fan set to low or off and then high.

Now you should have a delta of x degrees. The more significant the blockage, the smaller the temperature delta because the heat is not being exchanged from the air passing over the core.

Also, if you measure no significant difference with the HVAC fan set to max, this could be indicative of a blocked heater core. The delta should always increase with the HVAC fan set to maximum because the heat is being exchanged through the heater core.

The hot hose will be on the inlet side and the cooler on the outlet side.

When we backflush, we connect our water source (garden hose) to the outlet side to provide a backflush towards the inlet side. This helps to free up more of the crud collected inside the heater core.

After the backflushing process, the delta from the inlet to outlet should increase, if it was significantly blocked before you started.

This directional aspect is covered in most of the YouTube videos but if you don't see a reference in your video of choice, find another one that does. The direction is key. :cool:

Update:
My apologies but my original post had errors and I've updated the wording.

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Mister Luck

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But what I forgot to say is that I used the PowerWagon as service vehicle at the Rally Breslau 2022 - biggest Offroad Rally in Europe. So could that might cause the problem of a blocked heater core surface with brutal dust?
Let me reiterate ..
my previous post
Have you checked to see if it’s coils are clean ?
Air recirculating and circulating throughout your heater core coils theory of operation is behind the water circulation internally through the heater core itself…

… if air flow is restricted then the heat radiated from the heater core is not transferred efficiently.

check this post on cleaning and replacing cores and evaporators
 
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birchit

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The difference is simply the direction of flow.

You will be required to identify which hose at the firewall is on the inlet side versus the outlet side of the heater core.

If you have a laser-guided temperature probe, measure both hoses after warming the engine and record the temperatures of both for later in the process.

You might record a set of deltas with the HVAC fan set to low or off and then high.

Now you should have a delta of x degrees. The more significant the blockage, the larger the temperature delta.

Also, if you measure a significant difference with the HVAC fan off or set to low, this could be indicative of a blocked heater core. The delta should always increase with the HVAC fan set to maximum because the heat is being exchanged through the heater core.

The hot hose will be on the inlet side and the cooler on the outlet side.

When we backflush, we connect our water source (garden hose) to the outlet side to provide a backflush towards the inlet side. This helps to free up more of the crud collected inside the heater core.

After the backflushing process, the delta should decrease, if it was significantly blocked before you started.

This directional aspect is covered in most of the YouTube videos but if you don't see a reference in your video of choice, find another one that does. The direction is key. :cool:

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Thanks for that. I checked the temperature of the inlet side and the outlet side and it is almost the same by measuring it with a laser guided temperature probe. So it should be blocked in any way.

Thanks for the explanaition!!!!
 
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birchit

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Let me reiterate ..
my previous post

Air recirculating and circulating throughout your heater core coils theory of operation is behind the water circulation internally through the heater core itself…

… if air flow is restricted then the heat radiated from the heater core is not transferred efficiently.

check this post on cleaning and replacing cores and evaporators
Thanks....I have checked now everything again. Sensors, flaps, the tubes and everything working correctly. What I do not understand is, if the evaporator core is blocked and the heater core as well, how can the blower bring still so much air in the passenger room?
 

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On your Control HVAC Panel, does the left knob have any printing on it, that reads PUSH.
IF it does, with the engine idling & the Fan turned to the Low position,
press the PUSH button in for the count of 10 & then release, then do it again, hopefully a small light will begin to flash on the knob.
 
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RamDiver

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Thanks for that. I checked the temperature of the inlet side and the outlet side and it is almost the same by measuring it with a laser guided temperature probe. So it should be blocked in any way.

Thanks for the explanaition!!!!

If your HVAC fan was set to max and there is very little difference in the temperature from the inlet to outlet side, one of two things is happening.

The heater core is very blocked and not exchanging any heat with the air passing through the core or as Mister Luck suggested, the bulk of the air flow has been diverted away from the heater core by the door flaps not being in the correct position.

If no air flow is passing through the heater core, there will be no heat exchange.

PS: I had several errors in my previous post and have corrected the wording. My apologies for any confusion that may have caused.

What I do not understand is, if the evaporator core is blocked and the heater core as well, how can the blower bring still so much air in the passenger room?

A blockage in the heater core or evaporator is on the internal side where the coolant flows. The buildup of gunk prevents an efficient exchange with the air passing through them.

Think of the heater core and evaporator as being the same as the radiator but smaller versions, confined inside of a group of passages with a blower fan on one end and various outlet vents that are controlled by the positioning of door flaps.

I'll try to remember to post a pic of the HVAC duct system from my PC tomorrow.

If the core is gummed up on the inside where the coolant flows, that will have no reduction on the volume of air forced through the ducts and out of the vents.

Does that make more sense?


I don't recall if you have tested the outflow temperatures from the vents on both the driver and passenger sides.

Often, another indicator of a clogged heater core is a large difference in temperature from the same vent on different sides.

.
 
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