Bad heater core, what can cause this?

[CandiedYamz]

Hi all, my wife and I bought a used 2001 Focus SE Zetec Wagon this past March; its currently at ~107,000 km on the odometer.

I just got back from my mechanic who told me that my persistent issues with a slight burning smell from the heating vents, coolant leakage, too-slow defrost and excessive internal moisture are due to a ruptured heater core. Its not a cheap problem to fix for one that's not mechanically inclined.

I was hoping for some greater insight into how and why its heater core would blow out especially for a car only 4 years old and without any head-on accidents. I searched this forum hoping to find others who might've had this problem but it doesn't seem like a common issue nor is there any Ford recall as such. Could it be just my bad luck? Any gearheads out there who can enlighten me?

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[viney266]

The part is pretty cheap , but they are a PAIN to put in... They are known to be crappy on Fords. I had to put one in my bronco, ranger and my wifes old mustang...

There is really no specific reason I can think of to cause one to fail, other than it getting frozen.

...WELCOME to the Forum!

[CandiedYamz]

Pretty cheap, eh? My mechanic was quoting like ~$1,000 Canadian; I imagine from mostly from labour — he said something about getting behind the dashboard!

Does that seem like the going rate for such a job? Am I getting bilked?

Oh, and thanks for the welcome! :)

[CandiedYamz]

Man oh man, I've just been doing some online research and replacement cores are like $50-70 USD so I'm getting pretty damn suspicious about that ~$1,000 quote...

[Oni]

They're expensive to have replaced because they're buried behind the dash, which will take a while to tear apart and reconstruct properly. A heater core typically doesn't rupture but leaks due to corrosion. I don't know if you're familiar with it, but it's just like a very fine radiator except it's not for cooling, but to have the heat transfered off of it by blowing air over/through it. Also, once the coolants travels through your block and "picks up" heat, it'll reach your heater core and eventually travel back to your radiator. It is important to periodically flush your coolant system (not necessarily your fault per se) to cleanse it of any corrosive particles or chemicals that may have somehow entered the system.

My Thunderbird's heater core went out, and I remember the part being just around $100. I believe I was also quoted a guesstimate of around $400 to have the part installed. I'm not sure if it leaked due to corrosion or too much water in the cooling system. The coolant pipe running into the intake manifold on the car had a small hole formed by corrosion through the pipe. Then again, I also popped the safety seal (actual name escapes me) on my water pump due to too much water in the cooling system. The heater core leaked over a year or so after that event (started in the Fall with warmer weather - no freeze).

Your best bet is to flush the coolant system, and clean it out with several runs of fresh water and maybe a safe solvent. After that, there are plenty of coolant leak repair and sealants for you to use. Though, they're not always effective, it's a cheap alternative to replacing the heater core if it'll work.

I can't remember what I used, but it looked as though it had copper in it, and the liquid was clear. It was about $10-15 for the bottle at O'Reilly's. Though some people say they're a waste of money, after I used a sealant in my coolant on my T-Bird, I never did again have any heater core leaks. How did I know? No more condensation on the driver window and no more antifreeze leaking on the passenger floor!

Another option is to use liquid glass. It's a repair technique that's been around for a long time supposedly. Since the glass doesn't solidify until it comes in contact with air, it will stay as liquid in your coolant system posing no threat. Once it solidifies, you have glass sealant for all your leaks. You can pick liquid glass up at (oddly enough) pharmaceutical stores - i.e., Walgreens since that's where I worked and I asked my pharmacy about it. When I asked the pharmacy about it (that's why I said it's been around for a while), they told me they have a lot of farmers and such come in to request it for repairs on their tractors.

Hope that helps. Mine actually smelled like pancakes, so it wasn't so bad.

[CandiedYamz]

Thanks, ilcowil, lotsa good info there.

[Homer Simpson]Mmmm, pancakes...[/Homer Simpson]

[jboylan]

When my heater core went out on my blazer, I just rigged up a bypass line. Of course that's no good in canada in the winter. I was just way too lazy to take the dash apart, and I wasn't going to pay someone else to do it.

[viney266]

What you are hearing may be a bit high, but I have never done one in a focus. The part itself is cheap and the labor is a bear. I did one in a mustang, took me 5 hours !!I would get a second quote on that. It still may be 500-600 dollars, like I said, the labor is a bear..

[spydee]

I remember doing one on my parents old 95 escort. What a pain in the ass. We had to pull out the entire dash. Took my brother and I the better half of a day to do it.

[pspringe]

Don't put any of that junk in your system. It might fix your core temporarily, but it is also going to go through your engine block and radiator, where it is going to end up causing another problem.

The price you have been quoted is high. Part of the dash needs to be removed to access it, but it does not take that long.

Heater cores generally leak where the endtanks are attached to the tubes (whic run the length of the core). The endtanks are either plastic, and the crimps become weak over time or aluminum and the braze wears. Heater cores go bad over time and require replacement, just like many other parts on your car.