Heat not working after J Plug coolant leak

[iksnoved25]

Soo, I'm sort of fed up with this mechanic at this point. Very reputable guy, several friends recommend him...but idk, I guess I'm not getting the good vibes so far.

I had the b6 a4 in to get a coolant leak diagnosed. Ended up being the J plug, $400 parts, labor, diagnosis (including diagnosis of some other issues as well) seemed very well spent (considering people saying it was a PITA to fix themselves). Anyways, I get the car back and there is no heat. Any ideas? Air bubble in the coolant lines? I swear if I take it back and he says the heater core is broken I'm going to flip shit. It worked fine when I dropped it off and even had others in the car that were witness to that.

Anyone have any ideas? I'd rather have some sort of knowledge about what the problem is before I drop it back off so I know if they are trying to slip one past me.

Thanks!

[old guy]

Having no heat after replacing the coolant is a very common problem. The mechanic simply needs to bleed the system properly. There is still air in the heater core.

[Denio24]

Air bubbles in the heater core. Remove the hose clamp on the heater hose and pull back the heater hose until you expose the little hole on the top and you get a stream of coolant pouring up. Just be careful so you don't get coolant in your eyes. If it worked before then it probably still is fine.

[Charles.waite]

^^ what they both said.

A competent mechanic should have driven the car a mile or so, and refilled the coolant. Please check the coolant level ever day for the next few days, if theres a bubble that means there is a void and your bottle will start to get empty as the air gets purged and the coolant displaces it.

[crazyquik22023]

Dang $400 for a j-plug replacement. The thermostat assembly and j-plug cost about $150 in parts and takes me about an hour tops to install.

[jacobsen]

I just did my j plug and thermostat, it took me about 20 minutes. Accessory belt off, alternator off, throttle body off, hoses off thermostat, hard pipe out of the way, lube the new o oring with silicone, install, alternator back on, throttle body back on. Done. The bleeding take s a while and should be done after driving or at least running the motor. Hold the coolant tank up high and let the coolant flow down, it takes time... Crack the hard pipe and heater core bleeders after the motors cools down after each drive until none more comes out. I'm getting a big funnel that fits snuggly in the expansion tank, then I can run the motor with the coolant open and air can escape. The airlift suction jet fillers are pretty spiffy but I ain't got one neither, Well just see how the funnel trick goes...

[jacobsen]

400 for a thermostat is extreme rip off and any one who would charge that much isn't justified. Compounded by the fact they aren't even aware of the coolant bleeding trouble with this car I'd say they aren't worth your business. It's actually illegal to price gouge, you could go to court over these things if you find you've been ripped off. It happens every day. Small claims court hears these every day, all over the country...

[jacobsen]

Sorry to post so much but I just just checked and I got the thermostat for $55 on rock auto, an OEM Hella. Just take it as a learning experience, and for a learning experience you got off cheap lol Some people really get nailed.

[iksnoved25]

Wow.... Thank you all so much for letting me know. I'm bringing this Sh*t up to my dads attention. I feel like crap knowing he fit the bill for all this. I knew I could have done the control arms myself also....(a f-n $400 for parts and labor there, yes, I know they're $100 on rock auto. He mechanic said they were so beat up his guy didn't want to test drive it and he didn't recommend anyone driving it at all and milked it out of my dad).

Last time I take it there for sure.

[iksnoved25]

I called the place and dropping it off this afternoon.

I mentioned not having the heat and asked if he could bleed the system because of an air bubble. He mentioned he might have to also flush the heater core. Does this sound like something that would be necessary? Should I specify to ONLY bleed coolant system? If he does this heater core flush, I'm going to flip shit on him if he does this then charges me for it.

[Northern_B6]

I called the place and dropping it off this afternoon.

I mentioned not having the heat and asked if he could bleed the system because of an air bubble. He mentioned he might have to also flush the heater core. Does this sound like something that would be necessary? Should I specify to ONLY bleed coolant system? If he does this heater core flush, I'm going to flip shit on him if he does this then charges me for it.

Why are you going back to this shop?

Bleed the system yourself... Its free of charge and not difficult to do. It just takes a few tries.

[crazyquik22023]

Why are you going back to this shop?

Bleed the system yourself... Its free of charge and not difficult to do. It just takes a few tries.

x2 why are you going back to the same shop?? The coolant system should really bleed itself by just driving. But like Northern said, its very easy to bleed the coolant system. Since the car is not overheating though there is probably not alot any air in the system, flushing and bleeding the heater core is always a good idea. Here is a good question though. Did this shop install g13 coolant or use generic green coolant? My guess is there is probably green coolant mixed in with g13 now, which is known to clog heater cores. Check your expansion tank and see what color coolant is in there first.

[iksnoved25]

x2 why are you going back to the same shop?? The coolant system should really bleed itself by just driving. But like Northern said, its very easy to bleed the coolant system. Since the car is not overheating though there is probably not alot any air in the system, flushing and bleeding the heater core is always a good idea. Here is a good question though. Did this shop install g13 coolant or use generic green coolant? My guess is there is probably green coolant mixed in with g13 now, which is known to clog heater cores. Check your expansion tank and see what color coolant is in there first.

Why are you going back to this shop?

Bleed the system yourself... Its free of charge and not difficult to do. It just takes a few tries.

I'm going to do this when I get home. http://www.audizine.com/forum/showth...at-Suggestions

My thoughts were to take it back so they can fix the problem that they caused. If they say the heater core needs to be flushed, then flush it, but I won't be paying for it since the heat was a non-issue when i took it there in the first place.

The bill says "G12" and "Coolant x2"... I don't recall the color off the top of my head. I will check when I get home.

[iksnoved25]

I checked later yesterday. The coolant was bright pink in color.

After speaking with them yesterday, he said the heater core was clogged. I asked if it was bled in the first place and could that be the issue, his response was "these guys are good, certified Audi techs", which didn't really answer the question I had asked. He said these things happen, which was a BS answer. I told him screw it I'll do it myself if that's the problem because I'm not paying for it when it worked before it was dropped off. After voicing my strong opinion that the heat worked before I dropped it off, now no longer works, he agreed to flush it for me (without charge). Last time I'm taking it there, but glad it is all sorted out now. I did have distilled water in the coolant tank along with a very little bit of generic (premixed) fluid prior to dropping it off. The tank was empty and I didn't want to put just water in the tank and have it freeze between dropping it off and having him diagnose/fix the coolant leak. I still don't think 20 minutes of driving with a distilled water and distilled Prestone mixture would have caused this, especially when the heat worked while I was driving it over.


I want to thank you all very much for your help and suggestions. Believe me, I'll take care of this my own next time around.

[BARRY]

lol sounds like a situation i had when i went with my brother to have his thermostat and radiator replaced. they kept telling me its just the radiator...i told them i don't give a damn replace the thermostat AND radiator.

picked up the car, the guy said, you were right...the thermostat was bad.

[Northern_B6]

Glad to hear you're going to avoid this shop in the future. Maybe ask around your local forums/sub-forum for a reputable shop in the future.

I consider myself lucky to have a great indy Audi & VW specific shop in my city which I can trust.
The owners are really relaxed and take plenty of time to diagnose WITH me and take MY suggestions into consideration (even when I clearly state that I intend to do the work myself...)
He's even lent me his VW/Audi specific tools free of charge for my DIY

[iksnoved25]

UPDATE

So From Friday until Sunday, drove maybe 200 miles, the car seemed okay. The heat was hot, as in 69 degrees felt like it was blowing about 90. However, Monday I started the car and preheated it (had some snow/ice) and after about 15 minutes, it was lukewarm. 45 minutes of driving later, still about the same.

I called that shop to tell him it didn't work and that I haven't even driven it that much since then. He said "heater core". After back and forth a little, he said he can flush it again, or it needs to be replaced.

I'm going to try to bleed the heatercore line and see if that does anything.

Any thoughts? I still don't see how the car can go from perfectly fine after being driven only a few times (maybe 6 total) in the past year and a half, to now having the heater core die.

[crazyquik22023]

UPDATE

So From Friday until Sunday, drove maybe 200 miles, the car seemed okay. The heat was hot, as in 69 degrees felt like it was blowing about 90. However, Monday I started the car and preheated it (had some snow/ice) and after about 15 minutes, it was lukewarm. 45 minutes of driving later, still about the same.

I called that shop to tell him it didn't work and that I haven't even driven it that much since then. He said "heater core". After back and forth a little, he said he can flush it again, or it needs to be replaced.

I'm going to try to bleed the heatercore line and see if that does anything.

Any thoughts? I still don't see how the car can go from perfectly fine after being driven only a few times (maybe 6 total) in the past year and a half, to now having the heater core die.

Unlikely its air in the system at this point. Replacing the heater core is a fairly simple DIY job. And the heater core itself is not an expensive part. About $150 for OEM and as cheap as probably $50 for aftermarket. Since your only real problem seems to be the heat not working well I would replace the heather core. Here is a good DIY http://www.audizine.com/forum/showth...eater-Core-DIY Remember use G13 and distilled water ONLY when refilling with coolant. Do not mix any generic coolant with G13 as you said you did before.

[iksnoved25]

Unlikely its air in the system at this point. Replacing the heater core is a fairly simple DIY job. And the heater core itself is not an expensive part. About $150 for OEM and as cheap as probably $50 for aftermarket. Since your only real problem seems to be the heat not working well I would replace the heather core. Here is a good DIY http://www.audizine.com/forum/showth...eater-Core-DIY Remember use G13 and distilled water ONLY when refilling with coolant. Do not mix any generic coolant with G13 as you said you did before.

Thanks, I found that exact thread and was reading through it. I did mix distilled water and generic coolant, before taking it to the shop, where they drained and put fresh coolant in it. For a 15 minute drive and only being in there for a day I highly doubt the generic coolant/distilled water caused the issue, it even worked before. But, hear where you're coming from. I still don't get it. Worked perfectly fine, before taking it to the shop.

[jacobsen]

Thanks, I found that exact thread and was reading through it. I did mix distilled water and generic coolant, before taking it to the shop, where they drained and put fresh coolant in it. For a 15 minute drive and only being in there for a day I highly doubt the generic coolant/distilled water caused the issue, it even worked before. But, hear where you're coming from. I still don't get it. Worked perfectly fine, before taking it to the shop.

You have air trapped in your cooling system. You can clean your heater core with muriatic acid, it's a lot quicker than a whole new core. Get a sump pump and some ID hose and circulated back and forth through the heater core in both directions for 10 minutes or so. But I don't think that's your problem if it worked before you brought it there.

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[iksnoved25]

You have air trapped in your cooling system. You can clean your heater core with muriatic acid, it's a lot quicker than a whole new core. Get a sump pump and some ID hose and circulated back and forth through the heater core in both directions for 10 minutes or so. But I don't think that's your problem if it worked before you brought it there.

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Thanks Jacobsen. When I originally talked to the guy about flushing the heater core he's like "a garden hose isn't gonna do it, when we do it we do it with a special acid. We keep it in there for a couple of hours and let it do its thing". So either the guy never flushed it only bled it, or he flushed it and shit got clogged again, or he's right and it needs a whole new heater core. However, if I get a new core, wouldn't that just get clogged up again (using the mechanics logic of there being other gunk elsewhere in the system).

[jacobsen]

Thanks Jacobsen. When I originally talked to the guy about flushing the heater core he's like "a garden hose isn't gonna do it, when we do it we do it with a special acid. We keep it in there for a couple of hours and let it do its thing". So either the guy never flushed it only bled it, or he flushed it and shit got clogged again, or he's right and it needs a whole new heater core. However, if I get a new core, wouldn't that just get clogged up again (using the mechanics logic of there being other gunk elsewhere in the system).

Muriatic acid will definitely remove any crust in 10 minutes. And rinse away cleanly. I think what you need is thisuploadfromtaptalk1456336193065.jpg this will allow you to burp the system with the motor running.

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[iksnoved25]

Thank for your quick replies. I also think there is air in the lines. No reason why if it was just flushed 200 miles ago, that it would be clogged again. It has to be air.

[jacobsen]

Thank for your quick replies. I also think there is air in the lines. No reason why if it was just flushed 200 miles ago, that it would be clogged again. It has to be air.

Yeah if you don't seriously flush the whole system your going to crust up a new core... eventually... distilled only or the new fangled evans, be cool and get that lol

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[iksnoved25]

eventually... distilled only or the new fangled evans, be cool and get that lol

I'm sorry, but I have no clue what your talking about here haha

[jacobsen]

You're not supposed to fill the system with anything other than distilled water. Regular water has minerals that will deposit themselves inside your heater core. Otherwise there's a waterless coolant call Devin's which is mostly superior and non-toxic.

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[iksnoved25]

You're not supposed to fill the system with anything other than distilled water. Regular water has minerals that will deposit themselves inside your heater core. Otherwise there's a waterless coolant call Devin's which is mostly superior and non-toxic.

I did use distilled water with probably not even 10 oz of Prestone, which was only used to get me 15 minutes from my house to the shop. I had the coolant leak and didn't want to run the engine without anything in there. Also, it was 14 degrees outside, so I put a very little bit of prestone in there so the distilled water wouldn't freeze while the car was sitting overnight (fully aware that they would drain the system and put the proper coolant in there when the fixed the leak). Again, even on the ride over, I had heat. Ever since picking up from the shop it has been bugging out.

[jjvwg]

you should also pressure test your cooling system. I have heard of cases where people had a hairline crack in the system (typically on the plugged port of the coolant flange, not sure if the b6 coolant flange has a second plugged port, i know the 1.8t passats do) that would allow air to be drawn in right down to the heater core area. in that case you can burp the system all you want but you'll always wind up in same situation of having an air bubble develop.

[iksnoved25]

you should also pressure test your cooling system. I have heard of cases where people had a hairline crack in the system (typically on the plugged port of the coolant flange, not sure if the b6 coolant flange has a second plugged port, i know the 1.8t passats do) that would allow air to be drawn in right down to the heater core area. in that case you can burp the system all you want but you'll always wind up in same situation of having an air bubble develop.

Thanks for the response. I originally had thought that was where the leak was, because I couldn't find where the coolant was leaking form. I heard that could be a pita, so I decided to take it to the mechanic, get it diagnosed (assuming the flange was the issue) and bit the bullet and have them fix it. I assume when the leak isn't visible, they do a pressure test, so I'm pretty sure they did that. They said it was in fact the j plug that was leaking. I got the two of them confused and told them to fix it, because i thought the J plug was the PITA (if I knew it was as simple as an alternator replacement that I did 3 days prior, I would have done it myself. Who knows, maybe I wouldn't even be in this situation if I didn't get the terminology confused). The coolant level hasnt dropped since getting the j plug fixed nor have the coolant light come on since.

Based off everything I've googled, read and was suggested to me, I still think there is air in the system that just worked its way back to the heater core and screwing things up. I find it difficult to understand if it was flushed 200 miles ago, how it would become clogged again this quick. If that mechanic was saying, its the heater core that needs replaced, well, under the same logic (of junk getting caught in from elsewhere in the system) wouldn't that just happen again? If 200 miles is all it takes to get re-clogged again, then that cooling system is entirely screwed and needs replaced. Again, zero issues before it was taken to that shop. I don't see how the heater core would just fail with zero "warning". Heat was hot as well before I took it to the shop, no problems with airflow....


Either way, if burping it doesn't fix it, i'm taking it to a new place to get looked at. Maybe there is a leak somewhere, but the coolant level hasn't dropped...

[jjvwg]

do you own an air compressor? if you do, get yourself a vacuum filler and then you wont have to worry about air bubbles.

[iksnoved25]

do you own an air compressor? if you do, get yourself a vacuum filler and then you wont have to worry about air bubbles.

Negative on that air compressor I just watched a youtube video on that system and it would do exactly what I need it to do.

I guess I just find it hard to believe that the core needs to be replaced only 200 miles of being freshly flushed, when not experiencing an issue with the heater core before. That's all. I'm hoping its just some air. I'm going to try the bleeder hole on the heater core and burp the system later. Hopefully that helps.

[jacobsen]

You shouldn't need a new core. Get the lisle funnel or the airlift 2 if you can't burp the air out. It takes time. However, a common scenario is that the coolant system doesn't leak when pressurised or neutral but when the pressure contracts it may pull a vacuum and suck in air.

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[Denio24]

No need for an airlift. Create a vacuum using the bleed screw on the upper hard coolant pipe and the upper rad hose. Once coolant overflows, start the engine and put heat on high low fan, once it reaches operating temp bleed the return heater core hose by removing it partially. This may take a few shots, took me about 3 tries till i got heat.

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