Home Forums Gear Hunting Trucks and Four-Wheel Drives Heater Core Leak

Daughters cAr has a heater core leak.

Best approach?

Will a radiator sealer work until she has the money for a new core?

Depends on the leak. If it's a pin hole in the tubes, sealant might hold it. If it's a hose connection, probably not.

I never had much luck with sealers.Most are about useless with any antifreeze.
I had no luck at all with repairing one.If like newer radiators, they would be plastic.

Have her turn the heater off, so no more fluid runs thru it.
Once the coolant runs thru it and it leaks thru the heater ducts and defroster ducts,it's hell getting it out of there.

Can't dad lend her the money for a new core?

Probably getting it out/in in will cost more in labor than the new core.

See if Rockauto.com has one. They usually have the best prices on auto/truck parts

On a lot of newer vehicles, there is no water shutoff. The water runs through the core all the time. It's inside a box with movable doors that open and shut to control the air flow over the core. Shutting off the heat only shuts the door.

It's an 05 Mitsubishi Galant.

I looked it up and that one does have a shutoff. It's an electric solenoid behind the dash. If you turn off the heat, it should shut off the water.
Having the core replaced might get pretty pricey depending on what all they have to remove to get at it. This website says anywhere between $300 and $1000.
HEATER CORE

edited to add: I just noticed that even though I googled 2005, that site is for a 2002. It might not apply.

Thanks. I know labor will be the lions share especially here.

Yea,I have a 98 Dodge with a leak in the Air Conditioner tubing under the dash. The fix isn't too bad but $700-$1000 just to get at it.

The shut-off valve only stops flow, not pressure, as pressure in the cooling system rises with temperature. Remember, you have a core inlet and outlet, and pressure equalizes throughout the system. It will still leak when it's turned off.

As a mechanic Badger, what is your view on sealers?

Can't get it to your shop.

Stop Leak products are sketchy at best but typically they are a joke.
There is no free lunch on a heater core leak.
If you let it go, you'll have to watch coolant level and you will get a coolant stench in the cab.

To do it right, you have to fix it/replace it.
And that can be ugly depending on access to the core in your particular vehicle.

The leak stop worked for me a long time ago on a '67 Fairlane. Just hoping to get to spring for a real repair. Fully aware of the 'right' way to do it.

Vince- The kid is stubborn (where does that come from?) and independent. Insists on carrying her own weight.

Sealers are death to many components in modern cars. Heater core tubes and radiator tubes are typically much smaller in diameter than cars of old, and they will clog both. Best to bypass the heater core entirely by looping the heater hoses together until you can get it repaired.

That'll make for a long cold winter!

Thanks, though.

guy I work with has a Dodge pickup that had a heater core leak. he stopped it with Bars Leak or something of the sort. that was a year ago and still holding. IIRC, it took a couple of doses.

Best advice yet.
The longer it leaks the worse the stench in the cab.

Anti-freeze is corrosive. If it leaks on the carpet, it can ruin the carpet and also rust out the floorboard under it.

Saddlesore, Do remember back in the old days we used to stop radiator leaks with oatmeal, Had the heater hose come off the heater in a 39 Olds one night at the drive in movie and burned my girl friends foot and leg, now that was a real Rodeo, makes me laugh to remember it. Rio7

I think the timing is perfect.
Buck up, old man and get the kid's heater core fixed for Christmas.

Don't do the stop leak unless it's in a junker that you don't care about.
It can plug radiator capillaries, heater core capillaries and any small passageway that it might settle in.

If the vehicle is a nasty access number like a Grand Cherokee it will cost you $1000 +/-

:twocents:

Back when there was Zerone along with Zerex which was a alcohol based anti-reerze, I stopped a few leaks with Bars Leak.
I drove a 49 Plymouth for two years with a cracked block. Got so bad,I would drain the fluid our at night and put it back for the day.

With the coming of todays anti freezes,I had no luck with such leak stops