heater core flush (1 Viewer)

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Dec 28, 2006
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heater blows luke warm, not hot, on low. turn it any higher and it goes cold, the radiator was recently cleaned out at the radiator shop due to the massive amount of crud, made the engine get hot enough to shut the ac off. so is the heater core most likely also have the crud? newb question i know, icouldnt find any step by step on the flush, any help?
 
Sounds like you're jumping in mid-stream. Clogged heater core is a possibility, but really, you need to go in the following order:

1) Having the radiator cleaned or the system flushed does NOT mean the engine should be getting hotter than before; that's backwards! What's your temp gauge doing during all this??

2) While someone's in the cabin manipulating the heater temp lever, look under the hood near the firewall and make sure you can see the heater valve opening and closing.

3) Next would be to see if something's up with the t-stat.

Flushing the heater core would be somewhere down here...



Tell us EXACTLY what the radiator shop did. (And why was there so much "crud" in there anyway??) I'm more worried about your engine than your heater at this point.

Curtis
 
sorry, i didnt explain the situation. my mom in law bought it in july the first week she drove it she called me saying the ac wasnt working, i asked whta the temp gauge read, she said it 3/4 the way up. i told her to pull over and tow it home. i went over and looked at it, the reserve bottle was empty and rad was low, looking in the rad the tubing was all clogged, so she took it to modesto radiator, who then took it out completly and i asume he rodded it out and preformed some sort of flush . he mention it was one of the worst hes seen, even took pics of it. so the temp now runs fine, a little under half. i have since taken possesion of the vehicle. i checked the valve you mentioned, it does move, about 45 degrees of travel from one end to the other. with the fan on low and the temp slider on hot it comes out warm, turn the fan speed up, it then comes out cold, the rear air doesnt come out hot either
 
Ah. I see.

I "think" you can do a low-tech heater core flush by disconnecting the heater hoses and holding a garden hose to one of them, but let's wait and see what advice others have got for ya.

Cheers,

Curtis
 
Ah. I see.

I "think" you can do a low-tech heater core flush by disconnecting the heater hoses and holding a garden hose to one of them, but let's wait and see what advice others have got for ya.

Cheers,

Curtis

Excelent advice, I second that as well. The crud was probably loosened and is stuck in the heater core. Reverse flush it!
 
sounds good......how? and am i replacing the hoses whe i get them off or reconecting the old ones? is it the two hoses under the heater vlve or the two to the left of the heater valve?
 
sounds good......how? and am i replacing the hoses whe i get them off or reconecting the old ones? is it the two hoses under the heater vlve or the two to the left of the heater valve?

You install a hose adapter inline with the heater core hose, connect a garden hose to it and flush... There are kits to do that, if they can be found here in the boonies in Canada, surely you can find them anywhere in the good ole US of A... It's sold under "Radiator Coolant Flush Kit" or something like that.

As for where to connect the kit, it's got to be connected on the return hose from the heater, so that you may reverse flush the crud. Since the coolant was replaced, I strongly suggest you just flush the heater core itself, no reason to flush the whole engine and waste all that new coolant (unless what you see in the rad is so full of crud that it's got to be done for the whole engine).

I can't say more about the physical location of inlet and outlet with this particular engine configuration. You'll have to identfy them from a manual.

Clamp the part of the hose that goes from the flush adapter you just installed to the block and disconnect the heater inlet hose. That way you'll flush just the heater.

You may have to do this procedure a few times, there may be more junk floating around or stirred up. Make sure you have a jug of compatible antifreeze to top it up.

But have you talked to the garage about it? They should have flushed the system correctly, I don't see why you should have to do it (unless they say it's an extra charge and bill you for it)

HTH, keep us posted.

PS... be careful with the water pressure. If there is a real blockage somewhere IN the heater core itself (it's usually not, probbaly just accumulated at the heater core inlet), too much pressure will BUST the core. Maximum pressure, 15PSI. Don't open the valve all the way up, especially if your water pressure is really high where you are. It should flow with very little pressure. Feel the water hose, its shouldn't become stiff. If it flowes freely then you can open the faucet up a bit more to force flush the crud out.

Also, be careful with the force flush, be gentle, you may find that once you've done that, the core may spring a leak (you'll smell antifreeze inside and may find it fogs up more), if the crud blocked a pinhole and you just opened it up dureing the flush. You may need a product to patch the pinhole, like Barr's leak or something.
 
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I did on thread on complete flushing with photos.
May even be in the FAQ.
 
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I have done this on my 70 series. The heater blew cold all the time, so I hooked up garden hose and poured some flushing agent in and let it sit for about an hour. I used a product called CLR as a flushing agent and flushed in the opposite direction of flow that the core would normally see. Well at least I think I did as I did not verify. I surmized that the coolant came into the heater valve. CLR dissolves calcium type deposits and aluminum. The heater core in my 70 series is brass. If you plan to use CLR make sure your heater core is also brass. The front heater never got as warm as the rear, but it was certainly much better after flushing.

Karl
 
e,
i've tried to open the link to your write up in the FAQ but it just goes to the mud forums.
here's the link from the FAQ:
https://forum.ih8mud.com/index.php?board=2;action=display;threadid=15351
seeing those pictures would help a lot. not sure if admin could help...?

ahh, answered my own question with a more thorough search. is this the link you posted, e? if so, the link to it in the FAQ might need to be changed.
https://forum.ih8mud.com/showthread.php?t=14891&highlight=piece+flush+kit


thanks for letting us know, but seems like the link in the FAQ is fine. Hope the writeup helped some...
 

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