[Doug D]

You'll have to check but I think the aftermarket heater cores are aluminum. And it's a bear of a job. Basically the entire dash has to come out to access the HVAC box. And you might as well replace the AC evaporator while you're in there, but that will require a licensed AC tech to recover the freon and you may have to convert over to R-134a since R-12 is very hard to find.

When the heater core went on my '92 Acclaim, my fix was to temporarily T the heater hoses together (not fun as it was middle of winter) and I eventually replaced the '92 with a '90 Acclaim.

 

[phinxter]

It doesn't have a/c, so thats not an issue. The fogging is only a problem on cool mornings, later in the day it is ok. I'm not afraid of doing the job, I've pull plenty of dashes way worse than one of these, I just wish I had a visual indication like wet floor or something that tells me it is definitley leaking. I have owned the car since new (93) and it has never fogged like this.

 

[StarFire_MK2]

Yes, the aftermarket cores are aluminum. The OEM core was a copper/brass type, just like the OEM rad.

Yes, it is a big job, as Doug describes. I did it three years ago. Ugh. It's straight forward, but time consuming.

Have you checked for small holes in your floor? I had fogging issues with my car too, and eventually identifed that there was a rusted out area under the ebrake handle and in the trunk. These were allowing moisture in, which caused the symptoms you described.

 

[Doug D]

Check the drain that exits via the firewall. If you're not getting a wet or dampness inside, the leaking coolant is probably draining out via the firewall drain. That's what my '92 did in addition to fogging.

 

[phinxter]

well when I first start it up no fogging, I drive like maybe 2 miles and then it starts getting bad after the engine gets hot the defroster starts to help and after my 40 minute commute it isn't too bad, I even drive with the window open a crack but it doesn't help much although it used to. I'll drive her to work tomorrow and see what happens, one thought I had was the hot coffee I stop and get on my way might have caused it but I have been doing that for years. Oh BTW I have no firewall drain cause I have no A/C.

 

[B10alia]

Any sort of smells other than the slight coolant smell? I think you might be looking at something else, for a combination of reasons. These cars have full-flow cores, meaning all of the coolant flow goes through the heater core when the heat is on. Assuming you don't turn the heat of when you get out of the car, a leak in the core would be letting air into the cooling system. The 2.2/2.5 has a thermostat that is higher than the radiator, so any air bubbles accumulate at the thermostat and prevent it from opening, causing very rapid overheating. Have you cleaned your cowl drains (drains for the depression below the windshield)?

 

[neon98rt]

how does a car defrost without an AC? or should i say how does it do it well? the ac pulls out the moisture.

All it takes is a pin hole leak to fog up the car. You could always drill a hole in the bottom of the unit and see if you get a drip that way. And yes you have to pull the entire dash apart. You can cut a bracket in the dash and pull the front off but even after taking my dash apart i dont think the cutting way would be any quicker. Getting it back in took both hands and my legs...

I would leave your windows open a crack to let the steam out after you get home or else it will still be in there in the morning.

 

[Doug D]

how does a car defrost without an AC? or should i say how does it do it well?

Long ago I had a '79 Monza that was not equipped with AC from the factory - only heat. The defroster worked, just not as well as a vehicle with AC. The AC just helps remove the moisture. Thank goodness I lived in a dry state (Colorado) so AC was not really needed.

 

[neon98rt]

last year my ac didnt work and my window was always fogged up. I had a mini squeegie for the inside windows.

 

[B10alia]

I disabled the interlock between defrost and A/C on my Spirit, so if I want A/C with defrost, I manually turn it on. The windows do still defrost, just not as fast.

 

[phinxter]

well I have drove it a couple times to work, incluing today and swear I can smell coolant, and the fogging continues. I just got home and started looking around under drivers side dash and see nada. I look at pass side and see what appear to be some clean trails where a liquid may have run through the floor ducts. I see a couple small spots on the rubber floor mats, that are kinda brownish below the duct. then I lift the mat and it has a wet spot, yup thats it. I got a couple other vehicles to drive (less MPG) so I'll get around to replacing the heater core eventually.

 

[Bob Lincoln]

I disabled the interlock between defrost and A/C on my Spirit, so if I want A/C with defrost, I manually turn it on. The windows do still defrost, just not as fast.

I'm not sure why you would do that. The car is designed to engage the A/C when defrost is on so that the A/C seals will not dry out and leak. If you don't run the A/C in this manner year round, you are shortening its life by causing it to leak earlier.

 

[B10alia]

MPG concerns, Bob. That way I can run defrost for extended periods when it's cold and rainy to keep the windshield from fogging without incurring a penalty from running A/C constantly (especially in traffic). I engage the A/C when first starting out to defrost faster, and if the heater isn't cutting it alone. I also flick it on from time to time to prevent the drying you mention. It's mostly a preference thing; it requires a bit more thought on my part, but I've gotten used to it, and with gas prices what they are during the heating season, the small boost in MPG I get is welcome.

 

[Bob Lincoln]

The mpg penalty with the A/C running is only about 1-2 mpg, not enough to bother disabling the system. And historically gas is cheaper during the heating season, when the demand slacks off. You can't be saving enough money to make a real difference. If you go from 33 mpg to 31, and drive, say, 15,000 miles a year, you only pay $116 more a year, and actually, since this is seasonal, you're really talking about saving about $60-$70 a year.

 

[phinxter]

I just want to know how your getting 33mpg, or was that just a number for comparison because the best I can do is 29 driving 90% highway.

 

[Bob Lincoln]

My 5-speed Daytonas get 33 mpg, but my dad had an 89 Acclaim 2.5L 3-spd auto that got 30-34 mpg highway; 34 on long trips or with all highway. The trick is to keep it to 65 mph and be light on the gas.

 

[phinxter]

I live in upsate NY and it is a bit mountainous here, so maybe if I was driving on a straight flat New Mexico type road I would have a chance. I tried for 2 weeks once to keep it at 65 and the MPG wasn't barely measurable from 70. Mine is also an Automatic, I suppose an overdrive helps.

 

[jstew314]

well I have drove it a couple times to work, incluing today and swear I can smell coolant, and the fogging continues. . . I lift the mat and it has a wet spot, yup thats it. I got a couple other vehicles to drive (less MPG) so I'll get around to replacing the heater core eventually.

What about using a leak stop product like Bars-Leak?

 

[phinxter]

What about using a leak stop product like Bars-Leak?

I think it would probably work for awhile but If the inside of that core being brass looks anything like the old rad did I'm sure the whole thing would just clog up. stop leak is good to get you out of a jam but I would consider it a temp fix at best. Heck you can put some pepper or an egg in there and stop a leak. I already have the new core along with 2 new heater hoses.