Heater core slow death?

[Brianedwardss]

Lately it's been approaching the 80's around these parts, but my windshield is fogging up inside even in the mid day sun with the windows down. The fog lines are very clearly coming out of the defroster vents. I dont have AC. This occurs no matter if the fan is off or on, or recirculated or fresh air setting.

It hasn't rained in a while, and it hasn't been dewey either, so a plugged drain doesnt seem logical. This happens even if I've been on the road in the hot sun all day, in fact it gets worse as the day goes on.

So my guess is I've got a heater core slowly destructing...

T.I.A. folks

 

[Compu Doc]

You probably guessed it right. I'd change it out now.

 

[ocnorb]

Sounds familiar...

Last year I bought a '62 Studebaker that did the same thing. New heater core and all was good. Got the car for nothing because the guy couldn't/wouldn't fix it. Had a slightly sweet smell when you first got in.

Took me a few weeks of cleaning the interior to get all the residue off everything. Sold the car for $900 more than I paid for it to a high school kid looking for a hot rod project.

 

[lotzagoodstuff]

If you really want to check it, or at least temporatily resolve the fogging, bypass the heater core and consider plugging one side and pressurizing it with compressed air to say 25-35 psi (what's your radiator cap expell pressure at?). If you see/hear the leak and/or see the gage slowly leak down, you have a bad heater core. Sometimes you can find the void and silver solder it closed, but if it looks green/weak in more than one spot, I'd opt for a new heater core.

Good luck.

 

[RLDSL]

For the price of replacement heater cores and trouble they can cause, it's worth it to just get a new one. Fairly simple access through the glovebox

 

[Brianedwardss]

Thanks guys,

So the heater core comes out through the glove box? I've got a new evaporator core I've been waiting to put in, do they both come out through the glove box?

Thanks again

 

[itsacrazyasian]

Thanks guys,

So the heater core comes out through the glove box? I've got a new evaporator core I've been waiting to put in, do they both come out through the glove box?

Thanks again

Evap core comes out from under the hood side. Don't need to pull the case, just pull the side cover. Really easy to do.

Heater core comes out from behind the glove box. Use MOTORCRAFT! I went though 2 parts store ones and they kept leaking! This is even easier to do! While you're at it, do the heater core bypass and your ac will be really really nice!

 

[Brianedwardss]

That's what I was looking for! Appreciate it, looks like I've got something to do next weekend. On something like a heater core, I'd only buy Motorcraft because I really don't want to do it over again.

 

[itsacrazyasian]

That's what I was looking for! Appreciate it, looks like I've got something to do next weekend. On something like a heater core, I'd only buy Motorcraft because I really don't want to do it over again.

Well the first one was given to me as a comp since there was a new parts company coming into town wanting my business...Luckily they are easy to do. Actually your truck, the heater core is easier than mine to do. Should take all of 15 minutes to do.

When i did my evap core, i left the accumulator attached and took them both out together. Installed new evap, installed cover, resealed everything with some dum dum tape and foil tape, installed drier, pulled vacuum, injected oil and charged. Been great ever since.

 

[RLDSL]

Not sure on that year, but the later ones , the evaporator cover , has 2 lower bolts that have to be accessed from inside teh passenger footwell just under the glovebox to finish getting the cover off

 

[Brianedwardss]

what's your radiator cap expell pressure at?

It's got a 7lb cap at the moment.. When I bought the truck it had a 16lb cap , First thing I did was get a 7 lb cap for the hundred mile drive home. Well it's still on there 2 years later. What's the best pressure rating to have? I don't tow or live in a hot climate (it's only hit 80 once since September here...)

And thanks for that tip RSDSL, I'll most likely be hitting you up in a couple weeks when I get the entire new AC system I have sitting in a box installed. Even being AC certified, I've still got questions cause I want to do it right the first time.

 

[RLDSL]

It's got a 7lb cap at the moment.. When I bought the truck it had a 16lb cap , First thing I did was get a 7 lb cap for the hundred mile drive home. Well it's still on there 2 years later. What's the best pressure rating to have? I don't tow or live in a hot climate (it's only hit 80 once since September here...)

And thanks for that tip RSDSL, I'll most likely be hitting you up in a couple weeks when I get the entire new AC system I have sitting in a box installed. Even being AC certified, I've still got questions cause I want to do it right the first time.

Just leave the 7 lb cap on there. Book lists either 7 or 13 lb. the 5 extra lbs doesn't doesn't raise the boiling point all that much
9 roughly 3 deg per lb so 15 deg ) and in your climate it shouldn't make a difference. The 7 is a lot easier on old cooling system parts..
Feel free to holler any time.