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chemical treatment for heater core


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well I have tried all that I can in hopes that my heater core in my 87 EA82 wagon was good, but Im sure now that it is bad.

 

got a laser temp gauge and it shows 192 deg on the thermo houseing, 100ish on the pipe going to the water pump. one heater hose is at 140 and 1 is at 78.

 

I dont have the time and place to change the heater core right now. Im working in the yard so if I take the seats and dash out they either get soaked or get eaten by my roomates dogs. What is the best chem treatment I can use to get some extra life out of it. I will be able to replace it in the next few months, but I need to drive it till then.

 

Also if theres a member around the portland/vancouer area who has done these before and wants some extra Christmas money I can pay. Not shop prices but I can pay a reasonable wage.

Edited by djellum
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You could pull both hoses off and connect some short tubes up to the heater core itself. Get some liquid drain cleaner (the kind that is safe for plastic pipes - NOT the acid type). Fill the core with it and let it sit. Flush it both ways with water and give it a try. If it doesn't work or worse yet ruins your heater core and carpet - You have been warned:brow: Good Luck!

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Thats all I have seed done as well.We poured super hot water n soap into the core and then back flushed. that helped...You checked the waterline "temp adjuster thing" on the inside firewall just before the core.I have seen those froze up and had to be opened manualy ,that got the water moving again..Good luck! bad time of the year to be without heat...OSF

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I checked the little lever on the side of the heater core box. its hooked to the dash temp selector, and it is tight and moves freely when you move the temp select. the temp selector can be used, its just that fully hot isn't very hot. it will keep the windows defrosted and cut the chill, but it wont really "heat" the car.

 

i know putting anything in there is risky, I just need it to be a temp fix. the heat does work though, so I don't have to do it. its just not heating well.

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I would try swapping the heater hoses around 1st. May flush the crud out of the core.

 

If you have a NAPA parts store near you, look for Mac's Radiator Cleanser. Stuff works great. You can leave it in the system longer than the direction say to, it won't hurt anything.

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I checked the little lever on the side of the heater core box. its hooked to the dash temp selector, and it is tight and moves freely when you move the temp select.
You might want to also check to see that the heater control valve is connected and actuating when the temp control is moved.

 

I dont have the time and place to change the heater core right now. Im working in the yard so if I take the seats and dash out they either get soaked or get eaten by my roomates dogs.

When I replaced the heater core in my '81 hatch I did not remove the seats. I dropped the steering column, disconnected the dash, and pulled it back from the firewall but did not remove it from the car. I could pull the passenger side dash back far enough to remove the old core, clean the cavity, and install the new core. By doing it that way, I did not have to disconnect all the wiring by the steering column and it was easy to re-fit the dash back to it's installed position. It might be different for an ea82, but it was a lot less work than I had expected. It was still a lot of work but it was much tidier than I had built up in my mind. Now I can practically re-heat a meal from my dash vents.

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I was under the impression that the EA82's didnt have a valve, the core was just part of the overall cooling system and the plastic box around the core took care of how much heat gets in.

 

far from an expert but that is what I have read.

 

i may try something similar on mine, but I will need to go tear apart a junk yard car first to see where stuff is connected. tbh if im gonna replace it Id reather just pull the dash. its a carb car so no computer to worry about, shouldnt be ultra difficult. its one of those repairs that last thousands of miles, so time spent now is not wasted I guess.

 

my goal is to find a hatchback soon if I can, so Id like to get it good enough to last a few months. if I decide to keep it ill tear it apart. it also goes to vent heat when im on the throttle and teh fan switch relay is going out so it needs a general heating system overhall.

 

btw, where is the heater control relay? i replaced the switch but no difference. only works on 3 and 4 (being able to let it run on 1 might help keep the temp up as well).

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The heater relay is one of the 4 under the dash and above the steering column. You don't have a problem with yours if the fan works on 3 &4. You have a bad resistor block. It is just above the passenger foot well. Easy to get to. May be repairable, but probably easier to get another from the wrecker.

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You could pull both hoses off and connect some short tubes up to the heater core itself. Get some liquid drain cleaner (the kind that is safe for plastic pipes - NOT the acid type). Fill the core with it and let it sit. Flush it both ways with water and give it a try. If it doesn't work or worse yet ruins your heater core and carpet - You have been warned:brow: Good Luck!

 

You could also try CLR. You can get it at Lowes or walmart. Use the same method as above. I have the same problem as you but mine is from a rats nest that is in the heater box, duct work and who knows where else. I aslo only have speeds 3&4. It's the fan resistor I pulled it and checked. There cheep @ rockauto around $40. Hope you get heat soon. I'm in the same boat.

 

-Rothell

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Is the fan resister the little thing with 3 wire coils in it at the bottom of the feater fan box? Kinda thing ???Thanks OSF:banana:

 

Yes it is. It's Black and is mounted with 3 screws one of which is shared with blower motor. At least that is how it is in my EA82 wagon. It is the blower motor control module/resistor.

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Hope this helps

 

-Rothell

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if you get the omms wrong it will just run a bitt faster or slower. the heater cores i take the end tank off opposet the hoses and rod it out then reinstall the end tank. Lotts of flux and use 50/50 lead tin soilder thiss works very good most are pluged with calcium and sillacon takes me about 45 min to remove from car and about a hour to repair core.

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Hey Rothell,Yes thats the thing right there..I would have thought it was a dealer item..So I think thats my problem then.No 1st or 2nd on the heater fan.. As far as pulling the heater core in 45 minutes..I would bet its the surgical method of removal...But then again,if a guy knows his stuff mabey he can open her up that fast.I always use a dremmal tool and do surgery...OSF Oh and Ivans,Good work on the heater cores.I used to do soder repairs on American rigs growing up.It seemed that they had more "meat "to work with.Way back i tried to repair a Subaru radeator and it just fell apart.I couldn't keep the heat from spreading and that was that.Now, lookin back we used a full sized torch... Do you use a small one?

Edited by old sub freak
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Pull whole dash 15 min drop coullum pull heater box out oh it helps that iv'e done about 60 of them and know every conector and clip and exactly what has to be undone and what dosent. The trick is to pull the whole dash in one peice dont take anything off it is only about 12 conectors two cables and a heater control conector. 45 min is the fastest iv'e been able to do the core in

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Pull whole dash 15 min drop coullum pull heater box out oh it helps that iv'e done about 60 of them and know every conector and clip and exactly what has to be undone and what dosent. The trick is to pull the whole dash in one peice dont take anything off it is only about 12 conectors two cables and a heater control conector. 45 min is the fastest iv'e been able to do the core in

 

Do you have a detailed write up on that? If not that might make for a good sticky. I'd rather not do the surgical method, I pulled out the dash cluster when I first got my car and it took me an hour. I still broke one of the tabs the one behind the defrost button, didn't know it was there:horse:

 

-Rothell

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yes even a plain old write up would be nice. I get the gist of it, but if you can point out the major bolts and clips it would help a huge amount.

 

If you get to yours before me let me know how it goes. Pics would be great. Thats what I'll be doing, just don't know when I'll get to it.

 

-Rothell

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i start with the ps side plugs for heater fan ac temp control ect lower bolt on ps side then top bolt ps and ds side do not remove the center middle bolt. Then drop the ecu and realys unplug the ds conectors only the ones that conect the dash to wire harness. And the vent control then drop columm down undo the vacume heater control main plug. Then the bolt on lower ds dash and the speedo from cluster. Have a assistaint hold the ps side of dash while you pull the last bolt center midle of dash then one person on each side gentaly pull dash away from car. Slowly to check for anything that may have been missed. Once the dash is out two bolts and two lines and the box comes right out. I can do it with my eyes closed is not that hard. The reinstall is exactly opposet. The most important part is nothing comes off the dash is removed in one peice.

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