drain O plus heater core

[T77911S]

the heater core in my jeep has been clogged for several years now. pretty much no heat in the winter.
i had tried the garden hose on the heater core to unplug it but no luck.
so i figured what do i have to loose if the drain O eats the heater core i have to pull it out anyway.
i let the drain o sit longer than i planned but when i went out an put the hose to it it flowed like it never did before. i flushed it quite a lot to get the drain O out and WALA! i have heat this morning.

anyone ever done this before?

[GH85Carrera]

I have had to replace two heater cores in my El Camino. I am not brave enough to put a caustic material in my copper heater core. If it does not start leaking on you maybe you got lucky.

I do change out my anti-freeze every two years.

[sc_rufctr]

I've changed the heater core in my VW twice in over 10 years of ownership.
It competently failed both times although the second time it was a much slower leak. Not a fun job.

Anything that may delay or negate the removal of the dashboard in a modern car would be worth a try IMO.

Good luck with it.

[stomachmonkey]

My Tahoe needs to be "burped" every winter.

I suspect a minor leak somewhere that over the course of a year results in an air pocket at the top of the heater core resulting in lukewarm cabin heat.

[vash]

My Chevy sounded like a burbling stream. The mech said that Dexcool stuff gels.

I would flush it annually.

[lendaddy]

The Draino is likely sodium hydroxide (Lye) which will not hurt or react with copper, brass, plastic or steel as best I know. It will however eat the hell out of aluminum so be warned there, it literally dissolves aluminum.

[berettafan]

timely post. I was just lamenting the lousy heat in my wrangler....maybe this post will give me the push to flush the heater core (though not with draino!).

[Rick V]

Originally Posted by lendaddy

The Draino is likely sodium hydroxide (Lye) which will not hurt or react with copper, brass, plastic or steel as best I know. It will however eat the hell out of aluminum so be warned there, it literally dissolves aluminum.

Not like there is any aluminum in a modern day vehicle, Radiator, heater core, cylinder heads, water pump, intake manifold, and on some never vehicles the block.

[yetibone]

The trick is to fill the core up with water first, then blow it out (from outlet side) with 90psi compressed air. Do this about a dozen times and see if that helps unplug the coolant passages. I've unstopped many a heater core that way, without damaging the core itself. Mostly 3.0 OHV Taurus' and 4.6 F150s' that were factory filled with G-05 antifreeze. I did fix a Wangler that had been overdosed with Bars Leaks this way too.

Water from your household spigot doesn't have the force necessary to move obstructions out of the flutes in the core. The Jeep's own water pump prolly has more power than a residential well pump, or a city tap at the meter. Air pressure has the force to do it, but no surface area to push with. Filling the core up with water (outlet side first) provides a medium to push with, and air gives a means to do the pushing.

Whatever you do, DO NOT USE DRAIN-O. The water pump, and T-stat housing wouldn't survive unless the residual acids left behind in the heater were neutralized before returning the system to regular use.

[T77911S]

i thouhgt about the air pressure thing too but was not sure how much it could handle.

well i thouht the fix was short lived. i went outside yesterday and there was a large puddle of water dripping from under the car. long story short, i had the air on defrost and jeep turns on the AC compressor(which i hate), even though the AC light is not on. so it was just condensation water.