Radiator coolant leaking into AC system?!
Senior Member
Joined: Oct 2019
Posts: 277
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From: Perth Australia
12 C200, 12 C180, 10 Fuso Warrior crew cab, 08 RTV ute, 05 Smart Fortwo cabrio, 09 Smart Fortwo
Just pull the dash out and replace it, That Bars leak stuff is for $500 cars not for decent cars, plus it will block everything up not just the leak.
I doubt something so new would have a pin hole leak, might be that the seal where the pipes go into the core, and no bars leak will seal them for very long.
By the look of your pictures you have to pull the dash to change the airbag, just drop the heater core out while you are at at.
I doubt something so new would have a pin hole leak, might be that the seal where the pipes go into the core, and no bars leak will seal them for very long.
By the look of your pictures you have to pull the dash to change the airbag, just drop the heater core out while you are at at.
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Junior Member
Joined: Oct 2019
Posts: 46
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W212 E-class
Just pull the dash out and replace it, That Bars leak stuff is for $500 cars not for decent cars, plus it will block everything up not just the leak.
I doubt something so new would have a pin hole leak, might be that the seal where the pipes go into the core, and no bars leak will seal them for very long.
By the look of your pictures you have to pull the dash to change the airbag, just drop the heater core out while you are at at.
I doubt something so new would have a pin hole leak, might be that the seal where the pipes go into the core, and no bars leak will seal them for very long.
By the look of your pictures you have to pull the dash to change the airbag, just drop the heater core out while you are at at.
P.S: the pictures I posted are old, before the car was fixed. The car doesn't look like the pics now. My mechanic told me instead of pulling the dash out, it's better to disconnect the heater core pipes instead. I asked him about the bar's leak stuff but he didn't know, but he told me to try it anyway, so idk.
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W212 E-class
to confirm you open it up so you can see it.. and then pressure test system...
Or remove it and pressurize on bench....
Stop leak stuff is temp fix IF it works BUT can do MORE HARM then good by blocking required passages ways inside coolant flow paths.
Could cause you to burn up engine which is worse then adding coolant every day.
FIX IT RIGHT - Save ya money and FIX it right or sell it.
Or remove it and pressurize on bench....
Stop leak stuff is temp fix IF it works BUT can do MORE HARM then good by blocking required passages ways inside coolant flow paths.
Could cause you to burn up engine which is worse then adding coolant every day.
FIX IT RIGHT - Save ya money and FIX it right or sell it.
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Joined: Oct 2019
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From: Perth Australia
12 C200, 12 C180, 10 Fuso Warrior crew cab, 08 RTV ute, 05 Smart Fortwo cabrio, 09 Smart Fortwo
My mechanic tried everything he can do to ensure that the leak is not from the outside. He concluded that the leak is internal where the heater core resides. However, the leak is still small such that it doesn't drip water, it just produces steam. Do you think it's still a bad idea to use bar's leak? I'm planning to use the head gasket leak if I'm going to use one, not the liquid aluminum, coz it says the head gasket seal is as strong as carbon fibre.
It is a big job to change the heater core and the job can be a bit daunting, but it is possible for the average person with some mechanical ability to do in a day, I have not done a E series myself but I would say its not much different to a W204 which I have done, there are plenty of Utube videos that can assist with the removal of components.
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W212 E-class
All those additives are only a temp fix and are not really the ideal fix, you can use it if you like but remember that if it fails again and it will, its not going to be easy with that crap in the system as it coats everything.
It is a big job to change the heater core and the job can be a bit daunting, but it is possible for the average person with some mechanical ability to do in a day, I have not done a E series myself but I would say its not much different to a W204 which I have done, there are plenty of Utube videos that can assist with the removal of components.
https://www.youtube.com/watch?v=o39LGEGrVZc
It is a big job to change the heater core and the job can be a bit daunting, but it is possible for the average person with some mechanical ability to do in a day, I have not done a E series myself but I would say its not much different to a W204 which I have done, there are plenty of Utube videos that can assist with the removal of components.
https://www.youtube.com/watch?v=o39LGEGrVZc
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W212 E-class
Ok.. I finally decided what I'm going to do... I decided not to use this stuff since I can't repair my car if this breaks it.. Also, there are tons of negative reviews, just as there are positive reviews.. But.. I decided to bypass my heater core instead of trying to fix it with this and take the risk of ruining my whole car... I'm not satisfied that I'm going to lose my heated seats, heater, and defroster.. but whatever.. I'll revisit my mechanic later next week and have him bypass the heater core.. By the way, when I suggested him to connect the 2 hoses of the heater core together to create a loop, he said no it's better to plug the input hose to the heater core rather than making a loop, an idea why?
Thanks
P.S: Regarding the original intent of starting this thread, my radiator was leaking trans fluid into the coolant and there was some coolant in my transmission. But luckily, there wasn't a lot of coolant in the transmission so it did not need to be completely disassembled, glad I caught it on time; although, it needed a good flush and a new gasket and filter. But my radiator had to be replaced alongside with my reservoir tank. My mechanic ordered a new Valeo radiator that is made for C class W204, but fits fine on my w212 and the car runs great. Now I only have to bypass the heater core to stop the fogging of my windshield.
Thanks
P.S: Regarding the original intent of starting this thread, my radiator was leaking trans fluid into the coolant and there was some coolant in my transmission. But luckily, there wasn't a lot of coolant in the transmission so it did not need to be completely disassembled, glad I caught it on time; although, it needed a good flush and a new gasket and filter. But my radiator had to be replaced alongside with my reservoir tank. My mechanic ordered a new Valeo radiator that is made for C class W204, but fits fine on my w212 and the car runs great. Now I only have to bypass the heater core to stop the fogging of my windshield.
Last edited by Saud Aljeziri; Nov 21, 2019 at 12:59 PM.
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Thread Starter
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W212 E-class
By the way! All the symptoms I had that concludes a heater core leak are when both the AC and heater are OFF! My windshield fogs up when both the ac and heater are off, non is on! The steam also comes from the AC vents when they are both off! I also feel heat from over the dashboard and the AC vents when they are off. Why am I getting heat in the first place when the heater is off?? this makes no sense.
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2010 E550, 273 Engine: 2012 S550, 278 Engine
By the way! All the symptoms I had that concludes a heater core leak are when both the AC and heater are OFF! My windshield fogs up when both the ac and heater are off, non is on! The steam also comes from the AC vents when they are both off! I also feel heat from over the dashboard and the AC vents when they are off. Why am I getting heat in the first place when the heater is off?? this makes no sense.
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,141
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From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Ok.. I finally decided what I'm going to do... I decided not to use this stuff since I can't repair my car if this breaks it.. Also, there are tons of negative reviews, just as there are positive reviews.. But.. I decided to bypass my heater core instead of trying to fix it with this and take the risk of ruining my whole car... I'm not satisfied that I'm going to lose my heated seats, heater, and defroster.. but whatever.. I'll revisit my mechanic later next week and have him bypass the heater core.. By the way, when I suggested him to connect the 2 hoses of the heater core together to create a loop, he said no it's better to plug the input hose to the heater core rather than making a loop, an idea why?
Thanks
P.S: Regarding the original intent of starting this thread, my radiator was leaking trans fluid into the coolant and there was some coolant in my transmission. But luckily, there wasn't a lot of coolant in the transmission so it did not need to be completely disassembled, glad I caught it on time; although, it needed a good flush and a new gasket and filter. But my radiator had to be replaced alongside with my reservoir tank. My mechanic ordered a new Valeo radiator that is made for C class W204, but fits fine on my w212 and the car runs great. Now I only have to bypass the heater core to stop the fogging of my windshield.
Thanks
P.S: Regarding the original intent of starting this thread, my radiator was leaking trans fluid into the coolant and there was some coolant in my transmission. But luckily, there wasn't a lot of coolant in the transmission so it did not need to be completely disassembled, glad I caught it on time; although, it needed a good flush and a new gasket and filter. But my radiator had to be replaced alongside with my reservoir tank. My mechanic ordered a new Valeo radiator that is made for C class W204, but fits fine on my w212 and the car runs great. Now I only have to bypass the heater core to stop the fogging of my windshield.
But, if you are worried about it why don’t you use it only on the heater core? Disconnect hoses and rig a small pump that you can pressurize the heater core a little bit with the Bar’s solution in coolant. Or just connect long hoses that you can raise up to create head pressure to press the sealant fiber in the leak(s). Then rinse it all out from the core and reconnect to the car’s system again. The small residue possibly left in the heater core will be no problem for the engine.
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W212 E-class
The danger with the Bar’s leak stop that people are afraid of is that it would plug some small cooling channels in the engine. I used it on my Tahoe that had porous head problem. It worked fine. I had no issues with it. It made the coolant black. It so what.
But, if you are worried about it why don’t you use it only on the heater core? Disconnect hoses and rig a small pump that you can pressurize the heater core a little bit with the Bar’s solution in coolant. Or just connect long hoses that you can raise up to create head pressure to press the sealant fiber in the leak(s). Then rinse it all out from the core and reconnect to the car’s system again. The small residue possibly left in the heater core will be no problem for the engine.
But, if you are worried about it why don’t you use it only on the heater core? Disconnect hoses and rig a small pump that you can pressurize the heater core a little bit with the Bar’s solution in coolant. Or just connect long hoses that you can raise up to create head pressure to press the sealant fiber in the leak(s). Then rinse it all out from the core and reconnect to the car’s system again. The small residue possibly left in the heater core will be no problem for the engine.
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2010 E550, 273 Engine: 2012 S550, 278 Engine
Doesn't the bars leak stuff need to be in hot water to work? If I just run it through the heater core it won't do anything, that's why it says let the car idle for 15 mins. Also, do the small cooling channels get plugged by stop leak under normal circumstances, I mean when they are perfectly fine; or there has to be a defect in them? Many people say don't use it and I read many reviews that said it works wonders.. so idk
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12 C200, 12 C180, 10 Fuso Warrior crew cab, 08 RTV ute, 05 Smart Fortwo cabrio, 09 Smart Fortwo
You mechanic by the sounds of it is not a mechanic, if he says just block the inlet and leave the outlet?, the system will still pressurise and the core will still leak, plus if that's his suggestion I doubt he would know which hose to block.
Is he the same person that told you to use bars leak?, do you think your local MB dealer would use or suggest that?, you need another mechanic that will replace the core for you.
Additive to fix leaks and smoky engines and the such are only temp fixes, you are just covering up a problem you are not fixing it, sure you might stop it for a short time but the next weak spot will appear and you will be at it again.
If you intend to fix the car this way, Maybe MB ownership is not for you and you need to go buy a Kia?
Is he the same person that told you to use bars leak?, do you think your local MB dealer would use or suggest that?, you need another mechanic that will replace the core for you.
Additive to fix leaks and smoky engines and the such are only temp fixes, you are just covering up a problem you are not fixing it, sure you might stop it for a short time but the next weak spot will appear and you will be at it again.
If you intend to fix the car this way, Maybe MB ownership is not for you and you need to go buy a Kia?
Thread Starter
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W212 E-class
You mechanic by the sounds of it is not a mechanic, if he says just block the inlet and leave the outlet?, the system will still pressurise and the core will still leak, plus if that's his suggestion I doubt he would know which hose to block.
Is he the same person that told you to use bars leak?, do you think your local MB dealer would use or suggest that?, you need another mechanic that will replace the core for you.
Additive to fix leaks and smoky engines and the such are only temp fixes, you are just covering up a problem you are not fixing it, sure you might stop it for a short time but the next weak spot will appear and you will be at it again.
If you intend to fix the car this way, Maybe MB ownership is not for you and you need to go buy a Kia?
Is he the same person that told you to use bars leak?, do you think your local MB dealer would use or suggest that?, you need another mechanic that will replace the core for you.
Additive to fix leaks and smoky engines and the such are only temp fixes, you are just covering up a problem you are not fixing it, sure you might stop it for a short time but the next weak spot will appear and you will be at it again.
If you intend to fix the car this way, Maybe MB ownership is not for you and you need to go buy a Kia?
now is definitely not the time to be telling me to buy a Kia. I've spent on my car about 8000 dollars on repairs only, on top of buying it. And the heater core replacement is just too much for me right now, that's why I was looking for alternate solutions. But I decided to bypass the heater core until I have the money to replace my heater. My mechanic's point of view about plugging one hose of the heater is coming from the fact that the output hose is usually empty when the heater is off; I.e. coolant doesnt run through it. That's why he suggested plugging in inlet only since that's how the car usually is. He also told me that he has done it before and it works fine.
Last edited by Saud Aljeziri; Nov 22, 2019 at 01:28 AM.
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W212 E-class
Then boil the water but it may be it is not about the heat. It is probably about the pressure that comes with the heat. Pressure forces the fibers in the liquid in the small leak cracks and seals them if the cracks are small enough. Your problem could be too big leak though based on how you have steam coming out of vents. I would try to just use it in the heater core. What do you have to loose anyway if your other option is to by-pass it?
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From: Perth Australia
12 C200, 12 C180, 10 Fuso Warrior crew cab, 08 RTV ute, 05 Smart Fortwo cabrio, 09 Smart Fortwo
Unfortunately the cooling system is pressurised and to have a empty hose would mean that there is air in the system, this is impossible due to the pressure and if it was so you would have a air lock which could potentially cause overheating in the engine , Most new cars the coolant flows at all times and the blend doors separate the hot side from the cool side.
In the old days when they had heater taps you could block 1 side as the tap blocked the other, but you would still have to block both sides the core and the hose that went to it.
As I have just removed a heater core a week ago, I can assure you that there is no heater tap and the core is plumbed straight into the cooling of the motor.
To bypass the core he will have to remove the wiper cowl to give access to the plenum, disconnect the hoses from the core pipes then run them back to one another with a joiner to actually bypass the core.
Sorry when you are talking about adding bars leak to a 4 year old car it sends a shiver up my spine hence the Kia remark, no one care s what you do to a Kia.
In the old days when they had heater taps you could block 1 side as the tap blocked the other, but you would still have to block both sides the core and the hose that went to it.
As I have just removed a heater core a week ago, I can assure you that there is no heater tap and the core is plumbed straight into the cooling of the motor.
To bypass the core he will have to remove the wiper cowl to give access to the plenum, disconnect the hoses from the core pipes then run them back to one another with a joiner to actually bypass the core.
Sorry when you are talking about adding bars leak to a 4 year old car it sends a shiver up my spine hence the Kia remark, no one care s what you do to a Kia.
Thread Starter
Junior Member
Joined: Oct 2019
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W212 E-class
Unfortunately the cooling system is pressurised and to have a empty hose would mean that there is air in the system, this is impossible due to the pressure and if it was so you would have a air lock which could potentially cause overheating in the engine , Most new cars the coolant flows at all times and the blend doors separate the hot side from the cool side.
In the old days when they had heater taps you could block 1 side as the tap blocked the other, but you would still have to block both sides the core and the hose that went to it.
As I have just removed a heater core a week ago, I can assure you that there is no heater tap and the core is plumbed straight into the cooling of the motor.
To bypass the core he will have to remove the wiper cowl to give access to the plenum, disconnect the hoses from the core pipes then run them back to one another with a joiner to actually bypass the core.
Sorry when you are talking about adding bars leak to a 4 year old car it sends a shiver up my spine hence the Kia remark, no one care s what you do to a Kia.
In the old days when they had heater taps you could block 1 side as the tap blocked the other, but you would still have to block both sides the core and the hose that went to it.
As I have just removed a heater core a week ago, I can assure you that there is no heater tap and the core is plumbed straight into the cooling of the motor.
To bypass the core he will have to remove the wiper cowl to give access to the plenum, disconnect the hoses from the core pipes then run them back to one another with a joiner to actually bypass the core.
Sorry when you are talking about adding bars leak to a 4 year old car it sends a shiver up my spine hence the Kia remark, no one care s what you do to a Kia.
could you please recommend me the parts I need to by pass the heater core specifically for a w212, from amazon possibly?
thanks
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From: Perth Australia
12 C200, 12 C180, 10 Fuso Warrior crew cab, 08 RTV ute, 05 Smart Fortwo cabrio, 09 Smart Fortwo
Never dealt with Amazon, But I doubt they would have anything, you local hardware with some pipe of the right diameter and some suitable hose clamps would be the go.
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W212 E-class
Ok so I'm in the garage now and they almost finished disconnecting my heater core. The thing is that the mechanic told me that disconnecting the heater core will cause the cooling system to rust! He didn't tell me that before disconnecting my heater but, is what he is saying true? He told me that he bridged the in and out of the heater core together but will that cause rust? I didn't understand him completely; he mentioned that in addition to bridging the 2 pipes, there are 2 open pipes that don't have coolant flow, and he said this will cause the system to rust, even till the radiator. So am worried now because he told me that the I have 3 to 4 months until the system rusts from the inside...
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W212 E-class
what a reassuring thing to say... First, I've chose this path instead of the bar's leak stuff coz everybody here and including you advised me not to use it, and advised that disconnecting the heater core is a better decision that using bar's leaks. Second, I'm only asking if what the mechanic said is true or not, i.e. will my system really rust. I wanted an answer based on your past experience, that's all what I'm expecting. im not expecting you to solve the problem for me.
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1922 Ford Model T / no OBD
I think you should look for different mechanic. All cooling system components are made out of copper, or aluminium.
Even those metals do corrode, they are rust-resistant in common use.
Even those metals do corrode, they are rust-resistant in common use.
