I smell coolant, need pic of inside heater box

[gp001]

I need a pic, or description, of the inside of the heater box. The drawing in the Ford manual doesn't give me the info I need.
I can smell coolant inside the car. It is strongest when I take off from a stop (say at a light). There are no signs of a headgasket failure (temps fine, no bubbles in radiator, no milkshakes, the exhaust smells fine, no white smoke (even at 6000+ RPM), and no power loss). It just smells like coolant is leaking somewhere (no leaks at any of the hoses on engine, at water pump gasket, them housing, or weep hole).
I rebuilt my heater box with a new core and seals a few years ago, but I don't remember what the inside looks like. I think the core might be leaking and I want to know how I can access the core area without removing the box. I can't go in through the right hand door because the trap door inside makes it darn near impossible. If I feed something down through the defrost tube holes will that get to the core area, or is there an obstruction? I just want to see if there is coolant/water in the bottom of the box

Thanks

 

[2nd Mustang]

If there is an actual leak, you should see the coolant inside the box through the fresh air opening on the passenger side, or on the crack of the halves of the box at the bottom. It may just be the clamps attaching the hoses to the heater core have come loose, as mine in my 67 coupe was a pain to tighten up after installation of new core and hoses. I think you just remove the defrost hoses from the box and you should be able to see the hoses and clamps if I remember right. I don't envy you, this is one pain in the butt job.

 

[67GTA-FB429]

In my experience, when the core starts to leak, you do not have to look for it. It TELLS you that it is leaking by dropping water all of the place. Regardless of the size of the hole. Happened in my 65 and my 67. Sometimes they just smell.

Why do you have the heater on in May??

side note: advantage of a big block....it generates so much heat, you don't really need a heater.

 

[gp001]

Should the bottom of the box be warm/hot to the touch? All heater controls are in the up (off) position.

 

[KillerKittyCat]

The heater core is part of your cooling system. In other words coolant is always circulating.
Try a simple bypass of the core and see if the smell goes away.

 

[67GTA-FB429]

Thinking about it a little more.
1) just pull the clips on the bottom of the case to see if there is water.
2) you may have a leak near the engine (hose leak) and the coolant is on the exhaust or heads and you smell it because it (the smell) comes in through the cowl and windows.

 

[gp001]

Just got back from another test drive.

Thanks for the replys guys.

I know the core is part of the cooling system that is why I suspect a leak there. I would like to feed something into the box near the core to see if there is any moisture in there. I am trying to avoid bypassing it for the same reason I don't want to just open the heater box and inspect; I am trying to avoid a mess. I also don't wat to change anything until I find the source and figure out why it is doing it.

I was all over the engine and there are absolutely no leaks at any of the hoses or gaskets. This is driving me crazy. I'll take a six speed fab/swap over this kinda crap anyday.

Is the bottom of the box suppose to be warm/hot to the touch ?

 

[KillerKittyCat]

YES!!!!!

 

[pabear89]

Quick test for core leak is turn on your defroster,
if there is a core leak it will throw steam on the windsheild.
Do you have a drain hole on the bottom of you heater box?
it will have a short flapper end tube thru the floor to alow water out.

PB

 

[67GTA-FB429]

I am sure that you did this....but you never know.

When you checked the hoses, gaskets, and clamps. Did you do with the engine running, warmed up and the heater controls (not counting the fan) in the ON position?

 

[gp001]

I've checked it with every possible combo. I even ran the temp up a little high then shut it off hoping the heat saok would build pressure and reveal a leak. But I got nothing. I'm gonna try to fish something in there today.

Thanks again guys

 

[67GTA-FB429]

GP: what have you found out about the leak??

 

[hungrymonkey]

my truck had a slow leak for a few months before finally gushing out. must of been a pin sized hole that grew.

 

[gp001]

GP: what have you found out about the leak??

Nothin yet. In one of my test runs last weekend I hit something that flew up and cut one of my hydraulic lines to my clutch. So, now I get to pull the trans to replace the hydraulic line from the bearing to the master cylinder. Fun, fun. THEN I get to return to having fun with my coolant smell

 

[2nd Mustang]

my truck had a slow leak for a few months before finally gushing out. must of been a pin sized hole that grew.

I know what you mean. I had a Taurus that had that smell, but no visible leaks. All of a sudden, a gush of coolant all over the inside of my windshield. Apparently the heater core had a very small leak that sprayed a mist that evaporated right away, until the gusher happened!

 

[hungrymonkey]

My truck started out as a smell, then a drip, then after a couple of months it let loose.

being the curious dumb ass that I am, I had to lean over and pop open the glove box to see why antifreeze was gushing from it. I ended up with a mouthful of the good green stuff

 

[2nd Mustang]

My truck started out as a smell, then a drip, then after a couple of months it let loose.

being the curious dumb ass that I am, I had to lean over and pop open the glove box to see why antifreeze was gushing from it. I ended up with a mouthful of the good green stuff

My Taurus started with just the smell, as the dash board is so congested, you can't see the actual heater. Though with the Stang, being that the heater box is exposed under the dash, I could see coolant drops on the floor mat and then the heater box halves were wet. Luckily caught it before a gusher sprung.