My 99 with 4.6 just started sending an antifreeze smell through the vents. No dripping visible, but I imagine it's the heater core. Let the fun begin. Any way to confirm it's the core before I see any drips? I think I have the blend door post saved, and plan to do the blend door while in there. Any other advice? Dealer or aftermarket core?

 

Usually a bad heater core will steam up the windows.

 

Just because you don't see any drips or signs of leakage....doesn't mean you don't have any.

Your nose is a good indicator of a possible issue....better get it soon or then you will get the internal window fogging.

that said, with the colder weather upon us....make sure to check your antifreeze level and test condition , meaning is it good to -30 to -40. Also make sure you take it out and get it up to operating temperature ....then do the ole nose test and look for leaks. Maybe you happened to be at a convenience store or at a light, around other vehicles and someone else was having a problem & gotta whiff of their issue.

 

Get bars stop leak radiator pellets crush the up and put in tank. Temp fix.

 

I couldnt see my leak either. Started as a smell, next day turned to foggy windows. Take the black trim piece at the bottom of the center dash off and look up behind there. That's where mine was coming down was behind that trim piece. You can also see the top of the heater core from the upper passenger side dash trim (just above the air bag) if you remove that.

Autozones replacement cores are built well and have a lifetime warranty. crimped and welded seams. About $42
Also you can order the Dorman replacement blend door which has the fixed collar for about $21 bucks through them. Rent the heater hose puller as well, makes it a breeze removing the heater lines.

Id make sure you pick up some replacement quick connects for the heater hoses. When you try to remove the clips from the old heater core to transfer to the new, you will probably break them.

Took me 9 hours solo

Youd be better off to avoid the gunky mess and bypass the heater core if you needed to buy some time. I advise against any quick fixes as they normally turn to bigger problems down the road. At least bars is the better of most but still...

 

Temp fix that can create many permanent problems.

 

my heatercore started leaking as a result of a head gasket that was going out. the leaking headgasket put too much pressure on coolant system and the heater core was the weakest link. i found oil contamination in my coolant. hopefully, yours is just a leaking heater core. theres a couple good articles with pics & everything. here's one of them: https://www.f150online.com/forums/hv...-pictures.html the word documents are what really helped. print them out.

I got about 30 baggies and put the screws from each page in it, makes reassembly much easier. driver side seat had to be moved all the way back to drop the steering column. take lots of pictures for yourself. it really wasn't that bad, you can do it over a weekend. make sure you get a good small cordless drill with the right bits. i picked up the heater core from local ford with them matching tousley's price. i also made sure to get the foam wrap that goes around the core. while i purchase new lines, i didn't install them.

 

I'm a visual person so I watched a series of youtube videos. Then went to town on it.

Once I watched these twice, It seemed I had already done it. Only once had to go back and look at the video for information.

BTW, you DO NOT have to unhook the 3 harness blocks from the drivers side. There is plenty of room to bring the dash out without doing so. On the other hand there are a few wires on the passenger side not mentioned in the video that need to be removed from the holding brackets to give you more slack.

 

When mine went out I got the same symptoms - smell in the cab and a leak near the firewall. Luckily this dude had opened a mechanic shop down the road and wasn't getting any business, he did all the work for $300.

That's one major plus about the Super Duty trucks, replacing a heater core involves just removing the glove box and a few other small items behind it.

 

Thanks for the help, I'm halfway through the job, ready for dash to come out. Seems to be hung up along the windshield. I watched the videos and the guy took out a lot more trim around the speedo than the word doc says, so I'm wondering about that part. So far the job isn't bad, the Word doc with actual color photos was a lifesaver. If I can get the dash loose I'll be home free.

 

There are a few fasteners holding the upper dash in that are behind and around the speedo. Take it out and you will see. Also, it helps to lift while your pulling outward.

 

I finally got it done, there were two screws under some trim covers at center of windshield. Unfortunately my antenna string broke and it fell into the hole. I want to thank the guy who posted instructions with color photos, that really helped the heater core job go well.

 

Ok, I got a quick question about the heater core for these 97-03 trucks. I have had mine break and replaced 3 separate times in the last year. The first time it happened, I had a recommended repair shop replace it. Because of their warranty, I did not have to pay for the repair after the first time, but I am just wondering why this is happening so often. Anybody have any clue?

 

electrolysis..? Even with that, it shouldnt break down that fast.

What brand of replacements did you use? Where are they leaking at?

 

They are using OEM parts. I did not replace it myself, but it broke again and it is already at the shop (still covered under warranty so I didn't bother looking for where the leak was). I will ask where exactly it is leaking tomorrow.