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Solved Is my heater core leaking?

masospaghetti

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I keep faintly smelling coolant but I have no leaks or oily residue in the vents or inside the vehicle. I noticed green drips under the evaporator box, right at the seam. I DO also have UV dye in the air conditioner, but I don't have any symptoms of an A/C leak.

Before I rip the dash apart, I want to make sure this is where a heater core leak would show.
 


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BrooklynBay

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974X4BLACKSPORT

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Check your heater control valve first, these are known to leak a little at the shaft as they get older in age. I changed mine 3 times before I got the (lifetime warranty) one, although it cost more money, so far after several years it has not leaked yet. Coolant slowly comes out the shaft seal and can run down the hoses and drip somewhere else, totally faking you out where the leak actually is. But then again it still would not be a bad Idea to check your heater core for leaks (another know part to fail with time).
 




koda2000

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Sure signs of a heater core leak are:

A sweet smell inside the cabin.
Wet/damp carpeting on the passenger side.
Fogged up/frosted windows inside the vehicle in the AM.
 




boominXplorer

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Pull up passenger carpet, if it's wet with coolant then it's most likely the heater core or the hoses at the firewall leaking around the clamps.
 




masospaghetti

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Thanks guys...good call on doing a pressure test.
 




lobo411

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Mine has always had a slight/intermittent leak from the heater hoses at the heater valve. I replaced the hose thinking that the rubber had gotten hard, but the leak didn't go away. The only way I was able to stop the leak was by putting a worm drive clamp on the hose and tightening it with a socket and ratchet.

The leak was very specific, btw. It would never leak (as far as I could tell) when the engine was running. You had to wait 5 mins or so after shutoff, and then it would weep coolant for a few minutes. This produced a faint whiff of pancake syrup a few mins after shutoff and a slight residue in the immediate area of the leak, but no puddles, drips on the ground, or even enough coolant loss to notice the difference in the recovery tank.
 




masospaghetti

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Mine has always had a slight/intermittent leak from the heater hoses at the heater valve. I replaced the hose thinking that the rubber had gotten hard, but the leak didn't go away. The only way I was able to stop the leak was by putting a worm drive clamp on the hose and tightening it with a socket and ratchet.

The leak was very specific, btw. It would never leak (as far as I could tell) when the engine was running. You had to wait 5 mins or so after shutoff, and then it would weep coolant for a few minutes. This produced a faint whiff of pancake syrup a few mins after shutoff and a slight residue in the immediate area of the leak, but no puddles, drips on the ground, or even enough coolant loss to notice the difference in the recovery tank.

That's crazy that you just said this. I found the leak at almost this exact spot. I got a loaner pressure testing kit from Autozone (which was actually a really nice kit), testing was really easy and only took a few minutes to set up. Saw it dripping from the heater hose at the heater core - thought maybe the fitting was scribed, corroded, or cracked. Looked fine, tried reinstalling, still leaked during the pressure test. A worm clamp took care of it.

I have no idea why this specific joint needed a worm clamp when all of the other joints still had the factory clamps, even with new hoses.

But for right now I'm thrilled since it appears my heater core is OK.
 




BrooklynBay

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