Cleaning heater core and bleeding - 98 Audi A4 B5 AEB 1.8t Quattro

How I cleaned my heater core

[@smjanows]

Thanks, this worked on my B5 S4 Avant. It was -5F last night and I noticed that the air coming out of the vents was luke warm at best. I know I had more heat - a lot more - when it was -20F a few weeks ago. I changed the procedure a bit. I connected 3/4" hoses to each port - about 3-4 feet one each end. Then I used my air compressor to blow the coolant out - just held it by hand using the spray nozzle - alternating side, with my compressor set at 100 psi. I also dumped in a bottle of radiator flush fluid for about 5 minutes. Then I took some hot water (only because it's soft water versus the cold water which does not run through the water softener) and poured it through until I filled the gallon jug. I blew it out again, and then switched sides pouring another gallon through. I repeated this a few times - each time more sediment came out. Then filled it up, essentially getting all the air out, and connected the right hose, started the car, and waited to coolant to come out the bleed hole - none did after the car got up to temp so I just put it back on. Initially I didn't notice a difference, but then took the car for a spin around the block, and voila: HEAT. It was -3F out tonight.

[@aaron636r]

Awesome...awesome....awesome video. I haven't had heat in along time. Figured way too much to fix. 10 minutes doing what you did...HOT heat. Thank you very much.

[@Marksmanbbs]

Here's one Vermonter that wants to say Thank you,Thank you,Thank you,for your video.I have spent hours flushing and everything but use oven cleaner trying to figure out why my heater did exactly what yours did,my final thought was maybe i had a spent water pump,I luckily found your video b4 changing that and whallha,,,the thing was I couldn't find a bleeder anywhere then when you mentioned the hole in the hose,that was the answer I needed.1:30am n I went out and Wham!Excellent Heat!Thank You so much

[@martinee4901]

That plastic bit in the coolant was the inner rim edge that holds the seal in on the Rear Coolant Flange. Check that area for white powder, or leaking coolant as it warms up. A easy cheap fix. Check behind you vents for a thin grey foam sheet bits, or if it fits out the vents, it's the covering on the heater box flaps & probably what's causing the heater/aircon not to work 100%. If there's air comming out all of the vents when it should be just one, that's the problem. It's a epic fix to remove the box & recover the flaps in new foam, but worth it if you confident about DIY. I have done one so far without removing the dash, but stuck 1/2 way thru the 2nd because I can't figure out how to get the box back in.... It wasn't a problem on the first one. Try doing or checking a wrecked car just to get acquainted with it. You have to cut thru a centre vent ( hot wire & car battery ) to get access & then silicon glue it back on afterwards. Or remove the whole dashboard though that's a huge amount of work.

[@michaelellin]

U can do that with a water hose too. Slowly send water into the right hole and it will start flowing from the left side. Keep the water flowing until u see that it comes out clear. After that assemble as it was and That's it. I do this every year before winter on my Ford fiesta Mark IV and it runs like a charm, the cabin is heated in 5 minutes.

[@ClarksonFisherIII]

nice video, thanks! I have a tip you might like. to modulate the air that you're pushing through the hose, you could have taken not just the hose adapter from your blow gun but rather the whole blow gun. clamp that piece of hose you had to the end of blow gun and then you're set up in the same way but you can use the trigger of the blow gun to regulate air flow.

[@TheLastNightParty]

I had this problem for the last 2 winters. 2 years ago my temperature gauge stayed at low temperature. I changed my thermostat, it did fix my temerature gauge readings, but didn't fix the heat problem. Since then I couldn't figure out what's the problem is. Thanks for the video, I'll try to do it this weekend and see if it works. Just hope it is not faulty flap positioning motor.

[@brandondudycz6197]

You’re a life saver!

[@bobgedeon10]

The piece of plastic looked like part of a water pump impeller.

[@gregorythoman8281]

I've seen a lot worse than that. Anyway, you realize that the heater core is designed for around 15PSI? If you blast 150PSI through it you can destroy it. You were lucky dude.

[@joes.7536]

That plastic thing found in there was definitely from your water pump plastic impeller breaking off pieces.

[@bobbynelson2481]

I just did this and it done the trick thanks

[@spraym88]

great video👍👍

[@fountan1]

Hello, I had the same Problem with my Audi A4 B5 18T Bj.: 1998. Its the heat exanger (Wärmetauscher). It must be replaced because its tight with crap,...

[@carlosg815]

That is incorrect, the garage door was not closed. You can see when I opened the car door that the bright light from the sun was hitting the wall next to me.

[@peterdurnien9084]

Bleeding 5:33

[@rredmann100]

Hi carols I'm thinking this is the issue with my a4 i am only getting warm heat on my passanger side and cold air on the driver side do you think that my heater is blocked with gunk

[@dylanstallings5891]

Would a dirty heater core cause overheating

[@1thablu1]

before you flushed your core, was one of your hoses cold? I have no heat but both hoses are hot. thanks

[@Aco_s4]

Hey man can you tell me all the parts you used and the size of those hoses please thanks

[@gurvir44]

Great video, but watch out with the carbon monoxide poisoning. You had your car running with the garage closed.

[@Unshackledtruth]

Thanks for the information.

[@Oswaldom2]

dose the car have to be on when bleeding

[@mywisfilms7714]

У меня сейчас такая же 98года америка qwatro

[@carlosg815]

It's likely that your heater core is blocked.

[@bergz77]

were you getting your temp gage needle going to the half way mark when you werent getting any heat?

[@avega3325]

Hey did your temp gage go above the middle? mine has been doing that. not by much but it does go up. and i just bypassed the heater core. Just last night it stayed right at the middle for a good while

[@carlosg815]

Yeah the gauge was reading at normal operating temp but I got no heat.

[@avega3325]

***** Mine usually stays at the middle. but last night i kept driving it until the gauge needle stayed in the middle. im gonna go home tonight drive it for a while again and see if it stays the same.

[@carlosg815]

To my knowledge the car does not have to be running.

[@iansherman7964]

Now go ahead and flush that brake fluid.