OT Dakota Heater

I have a 97 Dakota that gives very little heat out the vents, barely keeps the windows clear when it's really cold. Pretty sure the heater core is plugged. I had to have a new heater core put in the 97 Ram and it cost $500 to get good heat out of it. This pickup isn't worth putting $500 into. Yes, it has been flushed and new anti freeze and thermostat, still no heat. It seems like I heard once that you could unhook the heater hoses and put drain cleaner in the core and then flush it out and it would clean it out. Will this work? Gonna snow tonite and get real cold, hate to start driving the gas hog Ram 4X4 this soon. Thanks, Chris

Hi I had a 99 Dokato that didn't heat, and like you I checked into replacing the core but it was too much money, I ended up flushing and using a weak solution of muratic acid but would not use that again had no problems and it did heat for the next 3 / 4 yrs. Drain cleaner may work its worth a try. Good luck
GB in MN

Take the hoses off the heater core and backlash the core, if you get a good flow then it is not plugged.

Turn the heat on, fan on high, engine fully warm, idled up. Feel the heater hoses.

If both are cold, no circulation.

If one warm, one cold, restricted circulation.

If both hot, something is wrong with the ducting, temp control, restricted air through the core.

My 98 Dakota with V6 heater was getting worse all the time. Seeing as how it was seeping antifreeze around the thermostat housing, I replaced the thermostat and gasket. That didn't help the heat. So, I just garden hose flushed the core. Didn't see anything that looked bad as I caught it all I a pail. Flushed it both ways. It heats a lot better now. Lucked out I guess. I had made up my mind I was going to ride cold rather than tear that dash apart. I had tried previously to get at the air intake from the outside by tearing off what ever I could easily from the outside. My cheapie bore scope didn't show me anything.

Same thing on mine, but I live in CA, so no biggie.

Alot of youtubes on Dodge heater cores.

https://www.youtube.com/watch?v=NEWDek-nNrU

https://www.youtube.com/watch?v=d9efkLn_NTc

https://www.youtube.com/watch?v=h_lHRcEXBs8

Back flush core:
https://www.youtube.com/watch?v=X_B1G9vNhms

Heater core valve:
https://www.youtube.com/watch?v=6eArgJuLjAk

Go to a combine salvage yard- Gleaner K, F, etc. had small units mounted on the floor...hot water heaters with a fan. About 6-8 inches square.

I might go with the muriatic acid, but I would avoid the drain cleaner. Most drain cleaners are LYE based (sodium hydroxide or potassium hydroxide) and would react destructively with the ALUMINUM heater core. Might I suggest a possibly plugged cabin filter? Or the blend door in the heater housing not operating? Seems on many of the later vehicles, the blend door is operated by a stepper motor instead of a cable. Just a few things to check.

Steve I like your advice and logic! I would just back flush with a garden hose cause the trucks systems are rated for no more than maybe 15 pounds of pressure? Most now are no longer copper cause aluminum is cheaper and actually works better. Stay away from acids! Also can have a busted heater valve in the lines from the engine. That was the trouble on a Ford Explorer. Valve is cheap and then you find the little vacuum controller hose is screwed up too. I have YET to have anything with a cabin filter but I have had so much crap on the core you needed to blow air backwards with a shop vac. or a huge air compressor on the inside with the vac. sucking on the imput side where the blower motor is. Take it out it will be easier. Quite a bit came out and then the heat worked. Dodge product. One other way if you can get into things is use the garden hose INSIDE the vehicle and back flush it and the shop vac will clean everything up. Messy but if you can get at it. My neighbor used to be an auto mechanic and had do do a couple of radiator cores for "friends". Good golly almighty headache you need to pull the dash, then the heater is part of the dash, then you take an angle grinder and cut into the rear of the heater box, THEN you can install a new core with a patch panel. I can remember changing the core on my 1964 Galaxie from the engine compartment in about and hour! Have fun!

When I had my 77 ford pinto and again last year on my 66 chevy c60. They were plugged bad and the garden hose trick didn't work. They were plugged too bad. So I went to the air hose trick. You need a air compressor with a tank for this. Make sure the heater core is full of water and blast it with a big slug of air. Refill with water and repeat. Do this several times from both directions.

It fixed both heaters. The Pinto cleaned up quite fast with two or three blasts from both directions. The C60 took like 10.

As the other guys said, flush the core only , with a garden hose , reversing flow a couple times. I also use the air hose to "shock" the crap loose too in between the water. Works every time. Dont use any chemicals. I believe on that Dakota you can also reverse the two heater hoses to run backwards which sometimes helps too. If you flush it into a bucket you will find what looks like sand and pebbles is what comes out.

(quoted from post at 21:15:55 11/20/15) Turn the heat on, fan on high, engine fully warm, idled up. Feel the heater hoses.

If both are cold, no circulation.

If one warm, one cold, restricted circulation.

If both hot, something is wrong with the ducting, temp control, restricted air through the core.

Click to expand...

Steve said it better than I would have but I wanted to mention that it may not be the heater core, it could be the controls. On my truck, a flapper can break due to age and it blocks heat from getting in the cab. Almost froze to death till I found it mentioned on the net what the problem was (flapper blocks air, use a coat hanger to prop it open), now I just freeze half to death, so I got that going for me.