Plugged ram heater core

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cappy2500

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I have a 2017 Dodge ram 2500 6.7 diesel the heater quit working they wanted $1,700 to fix it said it was a park heater core I took both hoses off the heater core took a garden hose put it in the discharge side of the heater core to back flush it a bunch of brown junk came out I ran water through it till it came clean and the heater now works perfectly. My cooling system was completely flushed at the proper interval and all the coolant is green except for the heater core and the radiator is clean I don't know how a sealed cooling system would even get brown sludge in it unless It is sand or something that came out of the block but before you spend any money with anybody just take both hoses off okay garden hose to the discharge side back flush it and see if that cleans it up and if you want you can take a little pump and then run radiator cleaner through your heater core for about an hour simple fix cost me $30 instead of $1,700
 

Rlaf75

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I do remember reading in a forum about sand from engine block castings but I couldn't imagine there being enough sand to cause that much of a problem. I guess it's plausible though. If it is a really problem I'm sure the dealers know about it but they would much rather you spend that $1700 with them instead of a few dollars to simply flush it out. Who knows though, maybe that's all they were going to do for that $1700. At least you saved yourself a $hit ton of money doing it yourself. Good job
 

Jeepwalker

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Good move! Quick, easy heater core fix. I've had the same thing happen on a vehicle I owned. There could be bits of gasket material ground up to bits, ...and did someone ever add hard water to the cooling system ...say, to re-fill after a coolant flush? Best to only use purified/distilled, or pre-mixed coolant ..but you probably know that.

Either way, now the heater works ..just in time for upcoming winter.
 

GTyankee

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I hope that i read you post incorrectly

you wrote

"My cooling system was completely flushed at the proper interval and all the coolant is green except for the heater core and the radiator is clean I don't know how a sealed cooling system would even get brown sludge ... "


which Anti Freeze are you using ?
 
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Wild one

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Way back when i was kid (dinosaurs were still getting in the way,lol) it used to be fairly common to flush and back flush the heater core on a yearly basis.The local radiator shop in my small town used to have a sign out front every fall promoting a heater core flush.
 

metalchewy

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Brown gunk to me, sounds like Bars Leak coolant system sealer. Similar to Alumiseal, except it has little resin pellets that seal vs aluminum. Maybe there was a small hole in the radiator at one point.
 

crash68

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I do remember reading in a forum about sand from engine block castings but I couldn't imagine there being enough sand to cause that much of a problem.
There have been several people reporting plugged on the HD trucks, for both engines available. Odds of both engines having a casting sand issue is slim as the engines built at two different plants.
My cooling system was completely flushed at the proper interval and all the coolant is green except for the heater core and the radiator is clean I don't know how a sealed cooling system would even get brown sludge in it unless It is sand or something that came out of the block
Ram has been using a purple OAT coolant since 2013, it does color shift from purple to an orangeish-rose color over time. I'd check whoever flushed your system used the correct type of coolant.
 

Burla

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Green coolant was the cause, rmi-25 that bad boy, it will take all of the slime and deposit it in overflow. Mixing oat and iat just never should be done.
 

dynocon

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2017 Ram 6.4, 70k miles original owner, never flushed or added coolant but now having little heat coming out. Top line to the core is very hot to the touch, bottom is warm so I assume it is partially plugged.

Are there any inline valves to control the flow or just plugged?
 

Jeepwalker

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I don't believe there are any inline valves ....but put your eye on it to be 100% sure. Try the backflush procedure outlined by the OP. Garden hose, reverse flow, give it a decent pressure. Watch for crud to come out. It's kind of a messy job, but worth it if it restore's you heat.

The ones I've done, an astonishing amount of crud came out. Restored the heater's output. Doesn't always work, but often it does. Your (previous poster's) 2017 truck isn't that old, so definitely worth a shot.
 
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dynocon

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Is there a special tool to get the hoses off of the heater core?
 

dynocon

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Or would it be better to take it apart at the connection appropriately center of the fender?
 

dynocon

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More research. If the heater is on high then one hose is noticeably cooler, if the fan is off both hoses are hot to the touch. Does anyone know what the typical temperature delta would be on a properly flowing core?
 

pacofortacos

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I do the manual flush and then for the final connection, I reverse the coolant lines vs. how they were and leave them like that - long term reverse flushing :)
 

GTyankee

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Mark your hottest hose, just so there is no confusion

Disconnecting the hoses at the firewall can be a bear

disconnect at the easiest place for you

run water or air into the colder hose, don't use a lot of pressure
remember, normally the was pressure is approximately 17 pounds

Your buildings water pressure is likely regulated at 50 pounds
 

dynocon

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What is everyone's normal operating temp? Just realized mine is running old school 185 consistently, replacement thermostat is 216.
 

gofishn

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do yo have enough heat in your climate system for comfort?

Engine temp is goign to be dictated by thermostat, generally, unless you have issues.
 

JmGuTe

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I do the manual flush and then for the final connection, I reverse the coolant lines vs. how they were and leave them like that - long term reverse flushing :)
Just did a flush on mine a few weeks ago, using an OTC flush gun and running prestone flush through it. Came across this tread and just reversed the hoses and there was a immediate difference. Definitely something to do since it doesn't hurt anything.
 
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