Possibly need new heater core

[Xist]

I have only driven my Civic here in Arizona and really only use my heater with passengers, but I almost never use my air conditioner, either. It was supposed to be 120° on Tuesday. It wasn't. I feel like having survived that, I do not need to worry for another year.

I always complain about my car being black. I wanted an HX. It took me several months to find Chorizo. I did not want to wait indefinitely (while driving my unreliable Forester) until I found a white or silver one. We talked about repainting or using Plastidip, but it never felt right.

Here I am, almost three years and eight months after I bought her and she started overheating on Tuesday.

No AC, just the window open, and I was driving 65. I turned on the heater full blast (oh joy!). Nothing. I stopped and adjusted my grill block. Nada. I felt I needed to slow down until I could get home and take off the air dam, but after I made it to my client, I checked my radiator.

I do not recall ever seeing the radiator fins.

I like to keep distilled water in my car, just in case, but I have gone through several bottles that leak and need to be replaced. I drove carefully to the nearest store and put at least twenty ounces of water in the radiator, planning on flushing today. I have not had any difficulty with the car overheating (it has been cooling off a degree or two each day since), but I have been topping off every day or two, and I topped off my fluids about three weeks ago.

I am definitely smelling antifreeze, so even when it is night, I open my window instead of using the vent.

Almost everything I read on-line says it is the heater core, with a few saying to replace the radiator. One time I topped it off I saw some water dripping a foot or two behind the radiator, but I have not seen that since, nor puddles, but they would evaporate quickly. There is a small damp spot on the carpet that I think smells like antifreeze, but so does the rest of the car. Neither the dipstick nor the oil cap show any water. There is antifreeze on top of the radiator, the top hose is crunchy, and there is antifreeze stain on the engine on the far side of the top hose, but I ran my car for about twenty minutes in the evening with the AC on full, headlights, and stereo. The engine was about as warm as it gets driving in the middle of the day (without headlights or AC). I pressure-tested the coolant system and it immediately lost pressure, but I could not tell from where.

Using KBB's "Fair" estimate, my car is worth $1,300. I looked at Civics on Craigslist and I would not look at anything for sale for less than $1,500, just the obvious problems seemed as bad as my car. I do not quite have that much and I have tax and student loan payments to make.

My Accord runs awesome, but I had wanted to fix the cosmetic stuff and have a pretty car while I drove my economical one. The best lifetime MPG anyone on this site got with a sixth-generation Accord with an automatic transmission was about 36, which is not a great deal better than I have done, although I drive 99% highway.

I kind of want to just top off the radiator each morning. It will get cooler and cooler, so that should be fine for a while, but one gallon of antifreeze each month being deposited all around Arizona does not sound like a very good idea.

Rockauto has the heater core for $40\59\70 (three different brands)
Pep Boys has Rockauto's $40 one for $90. Napa wants $111, and Autozone asks $121.
O'Reilly $122
Majestic Honda $251 (shipped)

It seems weird to spend ten hours replacing a $40 part, but I would not feel any better spending three times as much for the exact same part.

It seems weird to spend ten hours replacing a $40 part when the engine has low compression.

[cRiPpLe_rOoStEr]

Some folks in my country would pour cornmeal and egg whites on the coolant to seal a leaky radiator. But anyway, would you feel comfortable getting rid of the heater core and just carrying a jacket around? I've already seen some that are used by cyclists that are very lightweight and can be folded to a pocket size.

[Stubby79]

You can bypass the heater core, or you can put in some "stop-leak", or you can start replacing parts on a car that's on it's last leg. Your choice.

I'd probably do the easiest one first and see if it "fixes" the issue.

BTW, are you sure you're not burning it? Or perhaps you have a pin hole in a rad hose?

[Xist]

Burning it? Failed head gasket? I just did not see milk on the dipstick or oil cap, not have I seen white\blue smoke. My Forester had a bad head gasket, which I fixed. That was tedious.

Eric the Car Guy does not approve of stop leak and I do not want to disappoint him. He was the only one to wish me Happy Birthday last year.

[Fat Charlie]

I don't approve of stop leak- it's not a band aid so much as a tourniquet. Yes, it'll stop the bleeding right now, but you're causing additional damage.

I'd rather block off the heater core for real than add stop leak and gum up the whole system.

[Stubby79]

Originally Posted by Xist

Burning it? Failed head gasket? I just did not see milk on the dipstick or oil cap, not have I seen white\blue smoke. My Forester had a bad head gasket, which I fixed. That was tedious.

Eric the Car Guy does not approve of stop leak and I do not want to disappoint him. He was the only one to wish me Happy Birthday last year.

You can blow a head gasket without ending up with water in your oil. In fact, the last one of these I saw was on a mid 2000s honda. Fill up the cooling system and check for bubbles at the rad cap when you briefly open the throttle up.

[freebeard]

Take the two hoses I presume run to and from the heater core and connect them with a short piece of tubing. For diagnostic purposes.

Then consider a coolant leak into the cylinders. as Stubby79 suggests..

[Xist]

It was a cool 108° yesterday and I would have just used my vent were it not for antifreeze fumes. I had the same forty-five minute drive each way I did last week and my car was fine until I turned onto a side street, the engine started warming up quickly, but it had been uphill. Then there is a mile or two downhill, so my car was able to rest. I topped off the radiator after my appointment and drove home to try to do paperwork before my next client. My car was just fine on the freeway and highway, started running hot in-town, and started overheating when I was parking.

It seems I would be fine as long as I pushed my car into parking spots, but I just drove my gas guzzler.

I did not feel I could put off fixing it any longer, but I need to catch up on notes and start writing progress reports, so I am trying to focus on work and just driving the Accord.

I decided to take a minute and try to make sure that replacing the heater core would fix the problem. I had thought about bypassing it for diagnostic purposes, as Freebeard suggested, but I read:

Your heater isn’t working. Another glaring sign of a bad heater core is a simple lack of heat. While it could just be the blower motor or another part of the system that has failed, if you’re seeing any other signs it’s a definite indicator. There’s likely a hole in your heater core that’s allowing warm air to escape before it reaches your cabin. Depending on the size of the hole, you could be getting a luke warm breeze or none at all.

5 Signs Your Heater Core is Busted - Clean Machine Car Wash

I ran my car for several minutes with the brights on and the AC on max. It seemed to be at normal operating temperature. Then I turned off the AC and turned the temperature all of the way up.

It blew cool. Not cold like the AC, but cool like in the shade in the morning, before the sun actively tries to kill me.

I am still going to try to focus on work and consign myself to driving the pretty car, but I feel satisfied I know what the problem is.

[redpoint5]

Definately sounds like heater core. I wouldn't bother fixing it unless you plan to address the low compression issue too. Might as well bypass it to stop the leak though.

No need to put antifreeze in when it's leaking like that. Just use distilled water. You're probably not freezing in AZ anytime soon, right?

[Xist]

Supposedly we never got below freezing last year, but it would be easy to drain the radiator and replace with 50/50. So, one of these and two hose clamps?



Coolant has a higher boiling point than water. At least it keeps getting cooler outside!