How does one flush a heater core on a civic?
 

I am not sure how to do a heater core flush on a 7th gen civic.

I found these "generic" heater core flush video:


and



From what gather it is the same way with the 7th gen honda civic.

I can see the two hoses they are talking about on the civic.

I found a picture on here that shows the hoses I think they are talking about, the two connected to the firewall, I put a green dot on the two hoses:


http://imgur.com/a/VOLt2


So essentially I'll have to remove the airbox that is connected to the throttle body, pull that out of the way same with the air intake. And probably the battery and some more stuff so I can get clear access to those two hoses.

To make sure I understand here. Before that I first need to drain the coolant and then disconnect the two heater hoses from the engine side. With the heater valve in the full open position, blast water from a garden hose through the inlet hose and direct the outlet hose water under the car.

The inlet hose is the top green dot or the bottom green dot?

How do I put the heater valve in the full open position?

I heard I shouldn't use tap water for this, is that right?

I know they sell cheap kits at the local auto parts store for easy back-flushing with a garden hose. Was thinking of buying that and trying. Once I have all that taken care of I then flush it with pressurized water to get all the gunk out.

Thank you

Re: How does one flush a heater core on a civic?
 

if the system is taken care of properly with regular coolant changes it should never get to the point where it needs "flushing"

if your heater core is plugged, then take the hoses off and give her hell with the hose in the outcoming pipe....if its to that point you dont have anything to lose anyway,

why do you feel the need to flush it?

if you have no reason the flush it, just drain it and fill it....n most cases "flushing" does more harm then good

Re: How does one flush a heater core on a civic?
 

The car has a blown head and took bad advice from a family friend to pour in some blue devil. Before I could drive the car for an hour and then it would overheat, now I drive it for 1 minute and it overheats. Going to replace the radiator when it comes to my house. Since that white rock salt stuff is all in the rad that needs replacing. I guess heater core is clogged too, maybe the water pump and the entire engine too! :hithead::hithead:

Re: How does one flush a heater core on a civic?
 

good luck with that.....that crap turns to gum and will clog your entire system, you will probably need to replace the heater core and rad,

if you live somewhere where you can survive without using the heat then you could bypass the heater core,

i would remove the heater core and spray a hose into it full blast, i dont think it would help much but at this point you have nothing to lose,

Re: How does one flush a heater core on a civic?
 

First off find that family friend and punch him in the nuts.

Some people use CLR (calcium, lime, rust) liquid to help flush heater cores.
That blue spooge is worthless, nasty stuff. In addition to clogging a heater core it can clog a radiator and effect thermostat function as well.

[QUOTE=Niaboc67;4725853]blast water from a garden hose through the inlet hose and direct the outlet hose water under the car.[/QUOTE

The hose's psi water pressure shouldn't be any higher than the spec coolant system pressure for your engine. Higher than spec pressure could potentially cause leaks in the heater core.

The inlet heater hose is the one that has the heater valve (engine bay, near firewall) attached to it.

Set climate control to max heat.

The heater valves function is to allow a specific amount of hot (engine temp) water/coolant into heater core and is controlled by the climate controller. When the a/c is on and the climate control is set at max cold the heater valve is fully closed off. So, any temps in between max heat and max cold is controlled by the heater valve allowing in a specific amount of hot water to blend with a/c's (if engaged) cold air .

Tap water if fine for flushing heater core and/or coolant system but, use distilled water + coolant or prediluted 50/50 mix for final fill of coolant system.

The problem with tap water is minerals in it that can cause rust and corrosion if left in the coolant system for extended periods.

They work but problem is if you leave it in as part of the coolant system it can potentially become a weak point for leaks. You could choose to use it for flushing and then replace with a new heater hose but, it's an extra expense.

Re: How does one flush a heater core on a civic?
 

[QUOTE=Megalodong;4725918]First off find that family friend and punch him in the nuts.

Some people use CLR (calcium, lime, rust) liquid to help flush heater cores.
That blue spooge is worthless, nasty stuff. In addition to clogging a heater core it can clog a radiator and effect thermostat function as well.

Thanks for the advice!
Still confused on which is the inlet and outlet , is it the top of bottom in the picture?

Thanks!

Re: How does one flush a heater core on a civic?
 

It does not matter IMO. You will use the garden hose to pump water into it one direction, then pump it the opposite direction, and repeat this back and forth several times until it runs clear and flows freely without significant restriction.
Just make sure the heater hoses go back on the same as they came off.....but don't connect any of those until the entire rest of the cooling system has been thoroughly flushed.


On the plus side, blue devil (liquid glass, sodium silicate) mostly converts to cement in the presence of extreme heat, combustion leakage. So the stuff that got converted and became rock hard should only be in the head and block area.......whatever is in the heater core and radiator would probably still be kinda loose and flushable.

AND as Mr. Dong said, go punch that (air quotes) family friend (air quotes) in the sack hard enough his children hurt.

Re: How does one flush a heater core on a civic?
 

There are times when one has no choice but to use additives that clog up everything.
I have not one but three 2006 Honda Civics in my family that ALL sprung the coolant leak out stress cracks in the block.
The warranty was good for 8 years all 3 started leaking out of their blocks after 8 years at 90,000 miles, 120,000 and 260,000 respectively.
Two of three were saved from the crusher by Fiber lock. The fiber lock was put in the first one almost 2 years ago, and the other two 8 months ago.
two were cured, one failed. the fiber lock came out like oat meal on one. So we saved two Civics.. , but both have terrible heater core restriction now. That is why
I am reading up on generation 8 heating cores. my arms will not fit in the space to take the hoses off the firewall.

Re: How does one flush a heater core on a civic?
 

Can you reach if you remove the wiper cowl components from the base of the windshield?

Pull the hoses off at the engine instead of the firewall?

Re: How does one flush a heater core on a civic?
 

http://honda.oemdtc.com/264/low-heat...014-honda-cr-vhttps://cimg6.ibsrv.net/gimg/www.civ...089953a672.jpg
https://cimg9.ibsrv.net/gimg/www.civ...83722da781.jpg
https://cimg4.ibsrv.net/gimg/www.civ...d91d30fa8b.jpg
Harbor freight pump and 2 fittings from Home Depot . mix twice the amount by getting large bottle of CLR and 2 gallons of water. Pump will get hot because it is a transfer pump. I didn't drain system, car only has 60K. clamp off heater hoses to engine. You need the hose pliers to keep from damaging the heater hoses when removing from the firewall. Run for 2 hrs normal flow 1 hour reverse (twice the 1.5 hrs on the service bulletin for CRV's) flush with serveral clean buckets of water. Thanks to member EZONE . j.d.

Re: How does one flush a heater core on a civic?
 

Heyyy this is great to hear
Can you assemble and post all of the specific items you used (extra fittings, hoses, clamps, etc, i know the pic is up there but it's hard for me to read or see what they are) so a DIYer in the future has a comprehensive shopping list and play by play guide to the process ?

Re: How does one flush a heater core on a civic?
 

http://honda.oemdtc.com/264/low-heat...014-honda-cr-v
https://cimg2.ibsrv.net/gimg/www.civ...bcaa73e6f3.jpg
here are the fittings (teflon tape if desired when screwing into pump) , buy some decent 5/8 radiator hose (remember shorter hose can go from pump suction side into bucket, longer section from outlet of heater core down to bucket, and medium length from pump outlet into heater core), 4 basic hose clamps. look up the service bulletin from honda on CRV's. they show a filter screen on the pump outlet. I didn't need that. there were no particles in the bottom of the bucket.

Re: How does one flush a heater core on a civic?
 

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Re: How does one flush a heater core on a civic?
 

And good job keeping those numbers down too! There's a plastic key on the bottom of the radiator you can turn and drain about half the coolant with, and I think a no-spill funnel costs about what? $30.00? You don't want bubbles in your block. The coolant is designed to handle corrosion and deposits to begin with; you can try blowing it out, but if you neglect it for so long (maybe not your fault) that's necessary... I think you just need to take a good look at exactly how. big. a ****-up your ride is really turning into. My guess is the maintenance is just something you should enjoy, and nothing more. This "transfer pump" is not what everyone needs, but looks like fun.

Yours truly

Re: How does one flush a heater core on a civic?
 

If you're referring to the post about the CRV above, the issue is not caused by the owner nor neglect of maintenance.

Re: How does one flush a heater core on a civic?
 

Says you. Just drain and refill with the spec coolant a couple times. You're acting like it's water. If you forget about it for 10 years, don't come back acting like you're fixing something. Pro tip: it's already ****ed up!

Re: How does one flush a heater core on a civic?
 

Please find and read service bulletin 14-063 then get back to us

Pro tip: Bulletin link has already been posted at least twice in this thread

Please go to your glove box and get out your own owners manual and look up the maintenance schedules for for your own 2004 car, probably about p205 or so.
The manual says the first coolant replacement was due when?

Re: How does one flush a heater core on a civic?
 

Re: How does one flush a heater core on a civic?
 

:facepalm:

:popcorn2:

Re: How does one flush a heater core on a civic?
 

dude you're on very​​​ thin ice.
You may want to rethink that and apologize

Re: How does one flush a heater core on a civic?
 

If the car isn't due for maintenance yet there is no reason to perform that maintenance. The last pre maintenance minder spec was 10 years or 120k miles. CRVs that are affected by the TSB are having issue at 3 years old with 30k miles.

My personal car is a model that is known to have transmission failure issues. I change my ATF about 2-3 times per year and that is with less than 5k miles driven per year, but I get ATF pretty much for free so it isn't really an issue.

Telling somebody that they neglected their car when it hasn't come up for the very first service interval for that fluid is NOT productive. The first scheduled RDE is at 40 years. But some people are big fans of that procedure and may volunteer to get it early.

Re: How does one flush a heater core on a civic?
 

Is this a preventive maintenance procedure?

Re: How does one flush a heater core on a civic?
 

It sure is. I was going to use my google foo skills to give you a linkaroo, but it appears that my spelling skills and remembering skills suck at the moment. The acronym I meant to use is actually DRE instead of RDE. So I failed at google and typing, but my linkaroo skills are still top notch.

https://www.webmd.com/prostate-cance...al-rectal-exam

TLDR version is that it is the exact opposite of a UFIA.

Re: How does one flush a heater core on a civic?
 

:popcorn2:

Re: How does one flush a heater core on a civic?
 

Ah yes. The foot feels the foot when it feels the ground, my friend.

Re: How does one flush a heater core on a civic?
 

so, are you aware that is fake?

https://fakebuddhaquotes.com/the-foo...ls-the-ground/

Re: How does one flush a heater core on a civic?
 

It's as fake as these email notifications. How do you turn this off?

Re: How does one flush a heater core on a civic?
 

And what the hell does that mean?

Re: How does one flush a heater core on a civic?
 

ever head of FAQ?

https://www.civicforums.com/forums/f..._subscriptions