I looked and looked and couldn't find any posts with this particular problem.

Recently I started noticing I have a antifreeze mist coming out of my air vents when I start driving down the road. So I turn my air vents on high, and you can definately smell antifreeze coming out. I looked underneath to see if anything was leaking from the undercarriage, nothing. I felt around on driver side and passenger side floor board for damp wet spots, nothing. I can't seem to pin point as to where the antifreeze mist is coming from. I was recently told by one of my roomates friends that it has something to do with the heater core. I have a 2000 Dodge Durango SLT - 5.9L V8 Magnum. It has 130,579 miles on it and still runs strong like the day I bought it in 2004. I was wondering if anybody else had this problem before with the anitfreeze mist blowing out the dashboard vents and how to fix it?

 

If you see mist and can even smell antifreeze coming from your vents, you have a leaking heater core. My heater core went out at 40k miles and was not covered under extended warranty. If you get this replaced at the dealer, the cost will be around $600-$700 bucks. The OEM heater core part runs around $150 and comes with a 3 year part warranty. The remaining cost is labor. My personal mechanic changed it for me for half the cost. It took him 8 hours. As this procedure requires you to dis-assemble and remove the steering column and the entire dash assembly to gain access to the heater core that is mounted on the firewall from the inside.

If you have a good friend that is a mechanic and can do this for you, have your friend check the baffle door on the A/C system, after my mechanic put everything back together, my A/C ran much much colder. I guess that baffle door closes tight to prevent any air from going to the heater core to blend air with the A/C.

If it were spring/summer season coming up instead of winter, you can temporary bypass the heater core by disconnecting the two heater hoses from the firewall outside within the engine bay. Buy a 5/8th" heater hose coupler and connect the two hoses to it. This will prevent from further anti-freeze leaking and spraying into your interior cabin as well as dirtying up the A/C condensation drainage system.

 

Thank you Kensai for the responce. Looks like I'll have to start saving money to have it repaired since I know now it is a leaking heater core. Because usually if I leave the vents on high for about 5 minutes, the smell goes away and doesn't come back throughout the day. Just when I start driving after the trucks been sittin for day or two. But thanks again.

 

Another solution to your problem would be to run some alumaaseal through the cooling system (this is temporary I would not advise on doing this a lot). Only use one tube of the alumaseal and it will plug the hole in the heater core. If you do not have a clean cooling system I would not advise this at all because the alumaseal will not hesitate to block tight passages (like the radiator) and could cause overheating. if one tube does not plug the hole DO NOT use more alumaseal or you will have a better chance of plugging up the system. If you are mechanically inclined then changing the heater core is not a hard job it is just tedious. You will ave to have the a/c discharged though since you need to remove the a/c lines. Good luck with this. On a side note do not pour all of the alumaseal in all at once let it run through the system before adding more.

 

Thank you Mean Green, I'll try that first and if it doesn't plug up the leak then I'll definately replace the heater core. This will be the first mechanical problem I've had with this truck since 2004.

 

When you do get ready to replace the heater core, MAKE sure you VISABLY inspect the new replacement heater core before they install it. There may be a chance that they may install a bad core or a used core out of the box. Thanks to my friend's advice, the Dodge dealer parts guy had to remove 3 cores off the shelf that did not look good after I said, this core is not or does not look new. The first 2 cores, it had rust accumulation build up on them. The 3rd core looks like they tried to install it on a vehicle before. Then the last core, #4, it looked brand new and never been used. So I bought that one and had my mechanic install it.

When my core started leaking, you can smell it out from the vents when I moved the thermostat to warm, it did not smell much when it was on cold setting, but I knew the antifreeze already coated the drainage plumbing and still smelled the A/C. But the leak was very small. This leak occurred during winter so I did not have the luxury to bypass the core to wait until Spring time to change out the core.

Also, if you plan to do the temporary fix recommended by Mean Green and then later decide to have the heater core replaced, MAKE sure you do a very thorough flushing to clean up all that alumseal. You don't want to plug up a brand new heater core.

 

Definitely flush after changing the heater core. Thanks Ken I thought I mentioned that...

 

I recommend you bypass the old heater core using the 5/8th coupler as there may be a chance that you can push some of the alumseal into the new heater core. I would recommend performing a reverse flush on the cooling system. Prestone makes a kit for this. Basically the kit, you install a water hose coupler on the return side of the heater hose and then attach the water hose to it. Then you turn on the waterhose at full strength and this will flush out the sytsem in the reverse direction. When you do a reverse flush, you flush the radiator going the opposite direction of the normal flow of anti-freeze. Any alumseal that was pushed into the radiator core will be pushed out from the flow of clean water coming from the other end.

 

Wanted to give an update.

Before I could get a chance to flush the system and use the Bar's Leaks Liquid Aluminum Stop leak, my heater core has gotten worse with the leak. So now the heater core will definately have to be replaced because after I had pulled in my drive way yesterday and turned the truck off, steam started coming out of the dash board vents and my passenger side floorboard is completely wet from the leak. The antifreeze was coming out from under the passenger side dashboard like a water faucet left on low run. I called Advance Auto parts and they gave me a price of $42.69+tax for a new heater core and I have a friend whose a mechanic so I'll give him a call as well. Thank you for the helpful information, I appreciate it and will give another update after it's fixed.

 

If you have to wait a day or two for the core to arrive and still need to drive your D, you can temporary bypass the core by disconnecting both heater hoses and connect the hoses together with a copper coupler. The size should be a 5/8" diameter coupler.

$42.95 sounds a little cheap for a heater core for your Durango. When my core went out, I did alot of price hunting on the web and did not find one anywhere near your price. I would carefully inspect that $42.95 core and hope it is a quality core. My mechanic told me he seen some cheaply made core that has alot of plastics and other things. I went ahead and bought a OEM core from dealer. Cost is $150 vs $99 bucks at most aftermarket places. But OEM core has 3 warranty where most aftermarkets only has a 1 year warranty. The OEM core is solid metal and looks heavy duty compared to the $99 flimsier aftermarket version I saw.

Maybe this is a good time to see if the mechanic can build a door in the firewall for easy access as Hydra suggested to replace the core from the outside instead of a Dash teardown!