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Resolved Slow coolant leak dripping from passenger side frame rail.

  • Thread starter Thread starter Mindseye007
  • Start date Start date Apr 21, 2022
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Mindseye007

10 years still blowing strong
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#1
  • Apr 21, 2022
  • #1
My car was in the garage for winter Like the topic says check out my pic weird never seen this before.
 

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Monkeybutt2000

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Aug 11, 2019
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#2
  • Apr 21, 2022
  • #2
Most likely heater core/hoses.
 

Mindseye007

10 years still blowing strong
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#3
  • Apr 21, 2022
  • #3
Monkeybutt2000 said:
Most likely heater core/hoses.
Click to expand...
Is that not the same area where the A/C leaks out to the ground?
 

General karthief

wonder how much it would cost to ship you a pair
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#4
  • Apr 21, 2022
  • #4
Yes,
 

Mustang5L5

That is…until I whipped out my Bissell
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#5
  • Apr 21, 2022
  • #5
Mindseye007 said:
Is that not the same area where the A/C leaks out to the ground?
Click to expand...


Yes. When the heater core fails it leaks into the AC box and comes out of the hole that the A/C typicallly drips condensation. They also tend to leak in the car and travel under the carpet. I bet if you pull the pass side carpet back you'll find a pool of coolant and it's probably seeping through some of the seams in the floorpan and dripping from the subframe.

That's clearly coolant, so what I would do here is bypass the heater core for now and start planning on replacing it.


Autoparts stores typically sell something like this
Amazon product ASIN B09JHW9VSGView: https://www.amazon.com/Dorman-626-001-Engine-Heater-Bypass/dp/B09JHW9VSG/ref=asc_df_B09JHW9VSG?tag=bingshoppinga-20&linkCode=df0&hvadid=80539352771016&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584138875900065&psc=1
 
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Mindseye007

10 years still blowing strong
5 Year Member
Oct 21, 2020
578
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Apr 21, 2022
#6
  • Apr 21, 2022
  • #6
Mustang5L5 said:
Yes. When the heater core fails it leaks into the AC box and comes out of the hole that the A/C typicallly drips condensation. They also tend to leak in the car and travel under the carpet. I bet if you pull the pass side carpet back you'll find a pool of coolant and it's probably seeping through some of the seams in the floorpan and dripping from the subframe.

That's clearly coolant, so what I would do here is bypass the heater core for now and start planning on replacing it.


Autoparts stores typically sell something like this
Amazon product ASIN B09JHW9VSGView: https://www.amazon.com/Dorman-626-001-Engine-Heater-Bypass/dp/B09JHW9VSG/ref=asc_df_B09JHW9VSG?tag=bingshoppinga-20&linkCode=df0&hvadid=80539352771016&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584138875900065&psc=1
Click to expand...
What if I pull the factory carpet back on passenger side and it has not leaked any coolant? Completely clean and dry. What else could it be? Going to go check it later .
 

Mustang5L5

That is…until I whipped out my Bissell
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#7
  • Apr 21, 2022
  • #7
Mindseye007 said:
What if I pull the factory carpet back on passenger side and it has not leaked any coolant? Completely clean and dry. What else could it be? Going to go check it later .
Click to expand...


It's still coolant on your rail. It's making it from the core down to that area by some path. You'll have to poke around and see. Check under the carpet, check in the engine bay where the HVAC drain hole is. I've even seem coolant from a split core travel between the firewall and HVAC box spraying to the outside of the car. and coming out near the ECU.

My point is, there are many paths that the coolant can take from the core down to that area of the car. You're just going to have to dig around.
 

Cheapskate207

The left one hangs a little lower
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#8
  • Apr 21, 2022
  • #8
Read what mustang5l5. It’s likely the heater core. Very common. When mine failed my carpet was dry but I could watch coolant drip out of the ac box drain.
 

Mindseye007

10 years still blowing strong
5 Year Member
Oct 21, 2020
578
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Apr 21, 2022
#9
  • Apr 21, 2022
  • #9
Mustang5L5 said:
Yes. When the heater core fails it leaks into the AC box and comes out of the hole that the A/C typicallly drips condensation. They also tend to leak in the car and travel under the carpet. I bet if you pull the pass side carpet back you'll find a pool of coolant and it's probably seeping through some of the seams in the floorpan and dripping from the subframe.

That's clearly coolant, so what I would do here is bypass the heater core for now and start planning on replacing it.


Autoparts stores typically sell something like this
Amazon product ASIN B09JHW9VSGView: https://www.amazon.com/Dorman-626-001-Engine-Heater-Bypass/dp/B09JHW9VSG/ref=asc_df_B09JHW9VSG?tag=bingshoppinga-20&linkCode=df0&hvadid=80539352771016&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584138875900065&psc=1
Click to expand...
If I bypass the heater core can I still use my ice cold A/C ?
 

Mustang5L5

That is…until I whipped out my Bissell
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#10
  • Apr 21, 2022
  • #10
Mindseye007 said:
If I bypass the heater core can I still use my ice cold A/C ?
Click to expand...


Yes.


The unfortunate problem however is to replace the heater core, you need to discharge the AC to remove the HVAC box. There are more invasive ways of changing the core if you don't want to, but they involve essentially hacking the old core out with the HVAC box in place
 

7991LXnSHO

wanna catch the space herp
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#11
  • Apr 21, 2022
  • #11
Mindseye007 said:
If I bypass the heater core can I still use my ice cold A/C ?
Click to expand...
Yes.
 

evintho

20+ Year Stangneter
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#12
  • Apr 21, 2022
  • #12
If it turns out to not be the heater core, check the freeze plugs. They've been known to rust through from the inside out.
 

Mindseye007

10 years still blowing strong
5 Year Member
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Apr 22, 2022
#13
  • Apr 22, 2022
  • #13
7991LXnSHO said:
Yes.
Click to expand...
my heater still blows nice hot air too....
 

7991LXnSHO

wanna catch the space herp
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#14
  • Apr 22, 2022
  • #14
Mindseye007 said:
my heater still blows nice hot air too....
Click to expand...
If it stops blowing hot air, you have lost enough coolant that there is only air in the heater core, tubes, and who knows how much of the engine. That’s bad and potentially fatal.
Do you smell antifreeze with the heater or defrost on?
It’s time for a coolant system pressure tester.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
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#15
  • Apr 22, 2022
  • #15
Check those heater hoses too, they may be loose
 
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Mindseye007

10 years still blowing strong
5 Year Member
Oct 21, 2020
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Apr 24, 2022
#16
  • Apr 24, 2022
  • #16
Checked underneath carpet dry no leak of coolant anywhere pulled radiator cap off it made a fizz sound and the radiator is full to the top. The reserve was under cold line so I topped it up, added a tiny bit of coolant. Just going to leave it all looks good for now. Just that weird small leak on framerail. Checked hoses all good too.
Thanks for all your help with this problem guys. Going to take her for a drive 1st one this year. Do you think she be ok ?
 

7991LXnSHO

wanna catch the space herp
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#17
  • Apr 24, 2022
  • #17
No, I do not. The coolant came from somewhere and you have not fixed it’s escape route.

You need to use a coolant system pressure tester. Pump it up and let it sit. You will either have a good way to see it drip without the engine being hot and the fan blowing, or it will hold overnight and it will be a fluke.
You can also put some UV/fluorescent dye in, drive it a bit, then go after the leak with the UV flashlight like on CSI.
 
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Mindseye007

10 years still blowing strong
5 Year Member
Oct 21, 2020
578
135
63
ontario
Apr 27, 2022
#18
  • Apr 27, 2022
  • #18
7991LXnSHO said:
No, I do not. The coolant came from somewhere and you have not fixed it’s escape route.

You need to use a coolant system pressure tester. Pump it up and let it sit. You will either have a good way to see it drip without the engine being hot and the fan blowing, or it will hold overnight and it will be a fluke.
You can also put some UV/fluorescent dye in, drive it a bit, then go after the leak with the UV flashlight like on CSI.
Click to expand...
Let's say my heater core was plugged up, would that cause it to leak into the ac box and drip out the framerail?
 

Mustang5L5

That is…until I whipped out my Bissell
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#19
  • Apr 27, 2022
  • #19
The only source of coolant in the firewall is the heater core. The two hoses on the pass side are the only feed/return. Kinda means there is no other source for it to be. It’s just a question of how it’s leaking down to the frame rail
 

7991LXnSHO

wanna catch the space herp
10 Year Member
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Apr 27, 2022
#20
  • Apr 27, 2022
  • #20
Mindseye007 said:
Let's say my heater core was plugged up, would that cause it to leak into the ac box and drip out the framerail?
Click to expand...
A pinhole in a hose or a clamp that lets coolant by under pressure is likely.
Diagnosis is better than guessing.
If you are not seeing coolant inside, not smelling it inside and it’s not filming the windshield when the defroster is on, it might not be the heater core. They only told you it was likely, not absolute.
Test please.
 
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