My wife says she smells a antifreeze odor when the defrost is on. A buddy says maybe heater core. What happens when this goes bad? Causes? How do you know that it is this? And finally how hard of a job to change this core?

 

If there's a smell, then there is a leak. It can be a big job but do-able if your somewhat handy with a wrench. The trick, is it is located behind the dash, and behind, the glove box, way deep down in there. it takes alot of digging. The Gen2's dash was set on a pair of bolts that allowed it to rotate down and reach over and get to the heater core. I don't know about the Gen3's. I hope they still did that. You can bypass it if it becomes a sudden issue, by rerouting the in/out heater hoses. You will loose heat in the cab, but you keep driving.

 

Check to see if the passenger side carpet is wet underneath. If there's a leak it should be.
Could also be a leak under the hood and the smell is getting in.

 

If may also be dripping out of the ac condensate drain. Both core's are inside the same box.

 

Could also just be a leaking water pump and the HVAC is injesting the smell. Our trucks have superb noses.

I can smell a cigarette two cars ahead.

 

Ain't that the truth.

 

Thanks for all the replies. There are no leaks on my garage floor. Looked up changing heater core in Chilton and looks to be a pain in the ***.

 

Yeah, it would be a pain. The dash, and hvac box has to come out. Mostly time consuming, but not complicated.

 

For quite some time I'd been smelling antifreeze....but mostly once I was outside the truck. Finally tracked it down to a leaking oil cooler gasket. It was tough to find because it never leaked enough to drip but I was under the truck one day and saw antifreeze slowly making it's way down the lip of the oil pan. Tracked it back up to the cooler. No more smell now with new gasket set.

Something to think about.

 

Also 06's are known to develop a leak at the short section of 5/8 hose down by the turbo. Tightening the clamps usually does it, or sometime in 07 I think there was an updated hose.

 

i did a condensor on my 03 dodge 1500 and i went ahead and changed the heater core while in there. if the 2500 is anything similar then it is not difficult at all but more time consuming. the hardest part is remembering where all the screws went after taking them out.

note: make sure you remember where all the electrical conections are as well.

another thing to consider is while your in there go ahead and change your AC condenser. for me since my problem was originally the ac and i saw what a pain it was i did not want to have to go back in there when the heater core went out.

hopefully you dont have to go in there but if you do you will save ALOt of money doing it yourself. both parts are less then 200 bucks if i remember correctly. the mechanic wanted to charge well over 1000 to do the work.

 

On an older truck, while it was apart I'd probably change out the blend doors and housings to the updated parts, or put in the heater treater doors...