Heater Core Health Best Practice ?

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I never use my heat in my car until it's cold - however I'm beginning to think that might be a mistake . My mechanic said it is a good idea to run your heat once a week in a vehicle for a few minutes to circulate fresh anti freeze through the heater core to aid in corrosion protection ... Is this valid ?
 
Most cars have the coolant circulate through the heater core all the time and they still go bad.
 
i never thought about it but.. I think there may or may not be a valve or switch that shuts off the heating core when not in use?? Others have full time flow with an insulated door that closes blocking off the heating vent? Without knowing which one, yes its a good idea to exercise the heat. Probably a good idea to exercise the AC also?
 
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In the old days I recall a valve in the heater hose path which was used to amount of hot water into the heater core. On those setups, running heat once in a while would be a good idea. Then again, in those days it was 2 year coolant changes; and if the coolant could be trusted to "not go bad" all on its own in a car that was sitting for say six months, I'd think once a month, or every other month, would be sufficient to circulate fluid around.

Today I think nothing of the sort is used, and it's full flow all the time. But you'd have to check the model.

And they seem to still go bad anyhow. About all you can do is change your coolant when it's due. Perhaps a bit earlier even--nothing wrong with doing drain and refill at half intervals. That way the coolant never goes more than "half bad"; whatever corrosion inhibitors it has are never more than half used up (if the OEM recommendation is correct that is).
 
That is excellent advice for older cars where the coolant supply is valved to control heat and, especially, where the heater cores are soldered copper/brass. This technique was told to me many, many years ago and I also leave the heater valve slightly open on my toy cars to provide a slight circulation.

Most if not all 'modern' mainstream vehicles have a constant flow through the core so this is not the issue it was. Modern plastic and aluminum heater cores also seem to have much less corrosion issues...they fail in other ways.
 
Originally Posted By: LeakySeals
Probably a good idea to exercise the AC also?


You're either using it to cool the car or you're using it to defrost your windows. It's hard to avoid for any length of time.
 
A/C compressors usually will not engage if the outside temperature is below freezing. If you live where that is the case all of the winter, you really can't do much to "exercise" it.
 
I've never worried about "heater core maintenance" and have never had to replace one. My two primary vehicles (I'm 51 and am only on my third) were sold at 212,000 and 353,000 miles respectively.

Seems like an unnecessary thing to worry about.
 
if you listen closely the AC does engage when the front defroster is on to blow warm dry air up on thewindshield not hot wet air in the winter
 
Originally Posted By: wings&wheels
That is excellent advice for older cars where the coolant supply is valved to control heat and, especially, where the heater cores are soldered copper/brass. This technique was told to me many, many years ago and I also leave the heater valve slightly open on my toy cars to provide a slight circulation.

Most if not all 'modern' mainstream vehicles have a constant flow through the core so this is not the issue it was. Modern plastic and aluminum heater cores also seem to have much less corrosion issues...they fail in other ways.


Not sure how old the car would have to be. My oldest (1990) flows through the core 100% of the time, as do all the newer models I own.
 
My 60's era cars all had water flow valves that turned coolant flow off to the heater core. But all my newer stuff has continuous flow through the heater core (its often used as the thermostat bypass, in fact) and then use air blend doors to regulate cabin heat.

Blend doors produce an almost-instant change in temp wwhen the driver moves the heat selector, the old water-valve systems take a while for the hot water to get through the core, heat the metal, and start producing warm air so the driver tends to over shoot, get too hot, turn it down too far and it takes a while to cool off, then it gets too cold... lather/rinse/repeat. When I daily-drove the older cars, I always had a certain spot on the temp slider that I aimed for and then made very small adjustments.
 
Use the right coolant - Dex-Cool and many OATs lack the needed amount of azoles needed to protect solder - many older cars use soldered heater cores.
 
In further discussion with my mechanic - this statement is correct in that modern cars have fluid running though the heater core full time . Still , my heater core went bad in a Hyundai Elantra at 82K miles.
Originally Posted By: Chris142
Most cars today use a blend door instead of a heater valve. That means there is always flow through the heater.
 
Originally Posted By: nthach
Use the right coolant - Dex-Cool and many OATs lack the needed amount of azoles needed to protect solder - many older cars use soldered heater cores.



Non sense. I have a 20 year old Buick with the original heater core and radiator with a full diet of dexcool. Maintain it and it will last.
 
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I don't want to jinx myself. In 40+ years of car ownership, and I owned a lot of vehicles, I replaced 1 heater core. I maintain the cooling system by replacing coolant when it is called for, and I will occasionally forward and reverse flush the heater core if possible. For the time being it seems to be working for me.
 
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