Flushed my heater core with CLR. Lots of pics.

[catamount90]

Hey guys. Kinda new in this forum but have spent lots of time on the AW & QW 90 + B5 forums over the 10 years.

Anyway, I bought a nice looking B6 at auction a couple of weeks ago and have been slowly working on the TB/WP work. Now that everything is back together and running like a top, I'm trying to solve a "no heat" issue. I figured it had something to do with the coolant reservoir looking like a gravy dish.

After a couple of engine flushes, I set out to flush the heater core. Nothing new here, I copied ideas from several threads. Posting in here in case it might help someone else in the future.

First I took these stubborn guys off. If they haven't been moved in a while, it will take lots of pulling or a radiator hose pick.



Then attached some length of 3/4" ID hose.



I decided to first back blow the remaining water from the HC. Set the compressor regulator to 20 psi and made a night tight fit with some black tape.



Thought I'd give you a preview of some of the crap that came loose. Yikes.



I filled the core with distilled water and then blew in each direction a couple of times.

Then it was time to try out the CLR. I used the "drill pump" idea except I modified it with a Y-valve.



With one leg of the Y up in the air, I could top off the system and keep it full for better pressure.



In retrospect, it would've been easier just to have a buck with both ends of the hose in the bucket. And probably easier too. Oh well, this worked pretty well. I let it soak, then spun it in both directions, let it soak, then pulsed it.

Action shot:



Afterwards, I cycled a few gallons of distilled water through there to flush any remaining CLR. Blew that out with some compressed air also.

I didn't finish up until pretty late last night, so I've still got to burp the system before I know if my heating system improves. But with the amount of silt & scale that came out of there, I'll be surprised if this didn't help.

[kneel]

wow nice write up. I have a leak in my heat core hose, was looking into flshing everything out.

In for the results of this

[Toronto5.5]

Wow you went all out, good stuff.
Luckily on the B6 replacing the heater core isn't that big of a deal as it would be on a B5 or a VW of similar years.

Didn't know radiator hose picks existed! I'm going to pick one up now and flush my core too. I couldn't get the lines off.

[pimpbot]

Wow. Great method for the home brew flush. I'll have to remember this.

[catamount90]

Wow you went all out, good stuff.
Luckily on the B6 replacing the heater core isn't that big of a deal as it would be on a B5 or a VW of similar years.

Didn't know radiator hose picks existed! I'm going to pick one up now and flush my core too. I couldn't get the lines off.

Yeah, I didn't know either! I don't have one, but I read about them *after* I struggled with about every other tool I owned.

http://www.harborfreight.com/8-inch-...ick-96572.html



I'm adding one of these to my next HF order.

[felixdc007]

Ok I'm having the No heat issue too on my 2003 Audi A4 1.8T and I'm tired of it. I'm going to try to flush the heater core this weekend but I'm a bit of a newbie at this. Can I just try flushing the system with water? (I don't think I can replicate this setup) Also, can someone tell me step-by-step on how to "burp" or "bleed" the system? Thanks a bunch!

[aalipio]

Nice! Well done! Just replaced my heater return hose because it was leaking. Still need to flush, takes a lil bit to start blowing heat. Will use your home brew!
Thanks,


P.s. did this resolve your issue?

[VisionPaintball]

Update?

I plan on doing it this weekend.

[VisionPaintball]

Did mine today and now I have heat. Just used 2 pieces of 3/4"ID hose. Used a funnel and poured in CLR/water mix, let sit for 4 minutes,flushed with garden hose,repeat. Also took out the battery to make getting the hoses off easier.

[BARRY]

drill pumps are the absolute best. they're the choice for transmission/diff fill jobs as well.

[maestro.atish]

I am having the same issue of almost no heat. I took my 2002 a4 1.8t quattro to midas for a free check up and they said the heater core is clogged. They quoted me 1000$ to replace it and said flushing out the heater core doesn't help! 1000$ is a little too much and so I thought I'd give heater core flushing a try but I do not have any kind of compressor or pump to force water through. I was thinking that I'd pour water from the first floor of my apartment building to give it the pressure head. Would that be a good idea? Any other suggestions for someone that doesn't have a compressor?

[5TAK]

wow, you're quite a plumber

[old guy]

Any other suggestions for someone that doesn't have a compressor?

Yes. Get a drill powered pump for $10 as Catamount90 suggested and if that doesn't work you can always replace the heater core yourself for under $200: Clicky click

[maurizio]

It's threads like that keep me coming back to the AZ! Thank you

[vjborelli]

I am having the same issue of almost no heat. I took my 2002 a4 1.8t quattro to midas for a free check up and they said the heater core is clogged. They quoted me 1000$ to replace it and said flushing out the heater core doesn't help! 1000$ is a little too much and so I thought I'd give heater core flushing a try but I do not have any kind of compressor or pump to force water through. I was thinking that I'd pour water from the first floor of my apartment building to give it the pressure head. Would that be a good idea? Any other suggestions for someone that doesn't have a compressor?

Just stop by AutoZone and pickup a fluid transfer pump for like $15.
Run one side of the core to the transfer pump, and the other to a bucket.

Sent from my Banana Phone

[MikTip]

Awesome DIY post!

[maestro.atish]

alright, thanks for the suggestions guys, there's an autozone right next to where I stay so, the fluid transfer pump sounds like a good idea although I am just worried about the delivery pressure since I read that too much pressure (>10 psi) is not good for the heater core. would that be an issue with the fluid transfer pump?
two more questions:
1. when i disconnect the inlet and outlet hoses, will there be coolant gushing out like crazy or just a little bit of dripping that should be manageable (like placing a rag or something similar), just so that i can be prepared?
2. once i am done flushing, and move on to bleeding the coolant, again, will it be gushing out or only a little bit will bleed? and if the coolant is bleeding then won't the engine overheat (or not all the coolant bleeds, and most of it actually still circulates within the system)?

[vjborelli]

I can't find it on Autozone's website, but here is the almost exact same pump found on ebay. It is a hand pump, shouldn't damage anything at all.
http://www.ebay.com/itm/Performance-...ecebdf&vxp=mtr

[maestro.atish]

I found one hand pump at autozone too

http://www.autozone.com/autozone/acc...er=219982_0_0_

thanks.

[vjborelli]

I found one hand pump at autozone too

http://www.autozone.com/autozone/acc...er=219982_0_0_

thanks.

Don't know if you saw the price.... $208
Pretty sure that is for 10 gallon drums... Should only need a small hand pump like the one I posted to get the job done. Autozone has the one I posted from ebay... I just can't find the link to it on their site. The only difference I think, is that the Autozone one is white, and the pump top handle is a little different. Same exact design though. It is designed to screw onto something like a 2 liter bottle.

[maestro.atish]

So, I finally got all the tools needed. But when i got down to doing it, I couldn't open the clamp that holds the hose. Is there a special way to open it? Can that clamp be re-used when I put everything back together?

Also, when I opened the coolant reservoir to check the level, there was a hissing sound as if trapped gas just escaped (the car was off but still hot when this happened). Could there be an air bubble that was released or it happened because the engine was still hot?

[maestro.atish]

also, I ended up buying a drill pump as old guy suggested since that was available and yeah vjborelli, I hadn't checked the price for the hand pump I mentioned...what a foolish mistake, ha

[Matt Devo]

So, I finally got all the tools needed. But when i got down to doing it, I couldn't open the clamp that holds the hose. Is there a special way to open it? Can that clamp be re-used when I put everything back together?

Also, when I opened the coolant reservoir to check the level, there was a hissing sound as if trapped gas just escaped (the car was off but still hot when this happened). Could there be an air bubble that was released or it happened because the engine was still hot?

the cooling system is pressurized, hence the noise when you opened the cap while the engine was still warm. If you open it too soon after driving, you'll get hot coolant spraying out in addition to the air so be careful

[maestro.atish]

Ok, I did the heater core flush finally last night and got the hoses off...they were stuck real bad. After flushing in both directions I did notice that there was some silt that came through but I don't know if that was the reason for no heat because it wasn't a lot I thought. Also, after putting everything back together and trying to burp using the bleed hole, there was no coolant flow at all when the car and the heater were turned on. Could it be that there wasn't any coolant flowing because the engine was cold? If so, then that would mean that burping should be done when the engine is warm so that the coolant is actually circulating through the core?

Thanks.
Atish

[widgget]

Yeah, I didn't know either! I don't have one, but I read about them *after* I struggled with about every other tool I owned.

http://www.harborfreight.com/8-inch-...ick-96572.html




I'm adding one of these to my next HF order.

I made one of these out of an old screwdriver when i was trying to pull the heatercore connection under the hood a few weeks ago. works great.

Also did basically the same thing with the sections of hose and a compressor, but on the exit side rather then the milk carton i connected my shop vac and just sucked up the crap that came out (i didn't really care to look at the gunk since i was replacing the core anyway, just needed to drain it).

[audi.559]

can anyone tell me if the top heater hose is the supply and the bottom one the return?????

[diagnosticator]

I am having the same issue of almost no heat. I took my 2002 a4 1.8t quattro to midas for a free check up and they said the heater core is clogged. They quoted me 1000$ to replace it and said flushing out the heater core doesn't help! 1000$ is a little too much and so I thought I'd give heater core flushing a try but I do not have any kind of compressor or pump to force water through. I was thinking that I'd pour water from the first floor of my apartment building to give it the pressure head. Would that be a good idea? Any other suggestions for someone that doesn't have a compressor?

Just use garden hose water pressure. Cooling system flush kits have the fittings to fit a garden hose fitting.

[diagnosticator]

can anyone tell me if the top heater hose is the supply and the bottom one the return?????

Bottom hose is the supply to the heater core, top hose is the return from the heater core.

[diagnosticator]

Ok, I did the heater core flush finally last night and got the hoses off...they were stuck real bad. After flushing in both directions I did notice that there was some silt that came through but I don't know if that was the reason for no heat because it wasn't a lot I thought. Also, after putting everything back together and trying to burp using the bleed hole, there was no coolant flow at all when the car and the heater were turned on. Could it be that there wasn't any coolant flowing because the engine was cold? If so, then that would mean that burping should be done when the engine is warm so that the coolant is actually circulating through the core?

Thanks.
Atish

The heater has coolant flow regardless of engine temperature, or t-stat state open or closed. When bleeding air from the heater core using the hole in the upper return tube, the engine should NOT running, and the coolant tank cap is removed with the tank full to the upper Max line.

[diagnosticator]

So, I finally got all the tools needed. But when i got down to doing it, I couldn't open the clamp that holds the hose. Is there a special way to open it? Can that clamp be re-used when I put everything back together?

Also, when I opened the coolant reservoir to check the level, there was a hissing sound as if trapped gas just escaped (the car was off but still hot when this happened). Could there be an air bubble that was released or it happened because the engine was still hot?

For the spring type "Corbin" hose clamps There is a special hose clamp plier tool, made by KD, and sold in most auto parts stores. Makes releasing the spring type hose clamps a lot easier than using vice grips or similar. The KD tool has round pads on the tips, that rotate and with grooves in the pads to engage the spring clamp tangs. The hose clamp plier tool also has a ratchet to hold the clamp open without needing to be squeezed by hand constantly.



The Corbin spring hose clamps are reusable, and are superior to worm screw drive hose clamps, because they maintain a constant uniform sealing pressure all around the hose, and maintain a tight hose seal regardless of cooling system temperature, and compensate automatically for hose creep as the hose relaxes under the clamp after awhile.

[ddillenger]

Look up restore, and restore plus by Fleetguard. One is an oil remover, one is a mineral remover. After a treatment the inside of your motor and cooling system will be like new.

[Quattrim]

Not sure how to properly use "Restore Plus" to flush the Heater Core in my 2001Audi Quattro 2.8.
Did you follow the container instructions or did you modify that method?

[GoodMoodley]

Just an FYI for anyone who is considering this. I tried it this weekend and it worked great. I used a drill pump and actually had some 3/4 o.d. hose that was lying around. The hose actually slipped in to the inside of the heater core feed and return lines. Let the CLR sit for about an hour in the core and then used the drill pump forward and backwards a few times. Flushed it out with water afterwards, topped off the system and then burped it. Glorious heat on my drive in to work today.

[MurkyRivers_A4]

Just an FYI for anyone who is considering this. I tried it this weekend and it worked great. I used a drill pump and actually had some 3/4 o.d. hose that was lying around. The hose actually slipped in to the inside of the heater core feed and return lines. Let the CLR sit for about an hour in the core and then used the drill pump forward and backwards a few times. Flushed it out with water afterwards, topped off the system and then burped it. Glorious heat on my drive in to work today.

I did this exact thing on my sons A4 this weekend. I didnt let the CLR sit long enough though. Maybe 10 mins max. Got some nasty look shit out and his heater started working but not full heat.

Will have to wait until he comes back from Utah to do it again. Poor guy is gonna freeze out there.

[Chemmie]

I need to do this. Can someone confirm the hose diameter? Another thread states 7/8" ID and this thread states 3/4" OD. I'm assuming the heatercore inlet/outlet is 19mm ID and the 3/4" OD tube seals correctly?


Sent from my iPhone using Audizine

[maurizio]

A 3/4 inch heater hose from vatozone works

[GoodMoodley]

I need to do this. Can someone confirm the hose diameter? Another thread states 7/8" ID and this thread states 3/4" OD. I'm assuming the heatercore inlet/outlet is 19mm ID and the 3/4" OD tube seals correctly?


Sent from my iPhone using Audizine

My hose was 3/4 od so it slipped inside the core inlets with a bit of coaxing. I was lucky I guess. You should be getting 3/4 id so that it slips over the inlets.

[lostInTheSmoke]

Just did mine and wow this is all the shit that came out of it

Sent from my SM-G955U using Tapatalk

[fourtunaTTo]

Great writeup! Thanks!