heater cores, thermostats and negative double-digit temps! wanna join the fun?
CamoCivic
New Wagonist
Hey there wagon-fans, I've not had to do anything on my wagon this year, but now that tour season is over, and it's getting cold, I know I should do a few non-pressing things I've been putting off. First on the list, get heat in the car. Since I've only been driving it May-Nov the last few years, this isn't an issue, but since I moved to WY for this winter, and it's seriously cold (-24 a few nights back), I'm going to go ahead and replace the heater core. We flushed and power flushed and reflushed the core about 5 years ago, thinking that would help, but it didn't and I decided it was good enough. I can keep the windshield clear if it's above 20F, but not colder. I repainted my re-defrost lines last year, so maybe I should just drive backwards in the winter, eh?!! Nah, heat is a good, and I think I need a new core, so going to replace that. I've read the various sheets/forums here and it looks do-able. Going to do it over Thanksgiving (dad's heated shop, and more tools). Any tips? Any suggestions on which brand heater core is the best? Anything else I should look at once I've ripped into the heater core?
Also, I'll test my thermostat--I replaced it 3 years ago, for good measure, and it (and the older one) always runs 'cool', hanging at about 1/3 heat, instead of right at 1/2. Since both thermos showed 1/3 on the gauge, my gauge might be off? Or maybe it runs cool? I'd rather have cool, than hot. Anybody else have a temp gauge that runs just below the middle?
Details: 1990, rt4wd, w A/c.
Maybe I'll find a hockey puck and make some rear mount replacements, while I have the warm garage.
Wish me luck!
Also, I'll test my thermostat--I replaced it 3 years ago, for good measure, and it (and the older one) always runs 'cool', hanging at about 1/3 heat, instead of right at 1/2. Since both thermos showed 1/3 on the gauge, my gauge might be off? Or maybe it runs cool? I'd rather have cool, than hot. Anybody else have a temp gauge that runs just below the middle?
Details: 1990, rt4wd, w A/c.
Maybe I'll find a hockey puck and make some rear mount replacements, while I have the warm garage.
Wish me luck!
Comments
2. Is the heater core leaking? Just not hot enough? Poor air flow?
It's a real PITA to change, and unless it's gunked up internally with some kind of canned headgasket miracle the only reason to disturb it would be a leak.
Make sure the heater control valve/cable is adjusted to open fully. (More heat)
remove and clean the AC evaporator. ( air flow )
if your AC doesn't work, fix it. No 4th gen. Civic defroster works really well unless there's the dehumudifying effect of the AC. ( dry air )
IF you must remove the heater core, the easiest (maybe the only) way is to remove the entire dash first.
there is no cabin air filter, and the face of the evaporator is where all the debris stops. The fan sucks dirty wet air from the cowl area. It really does make a dramatic difference to remove the leaves and straw and bird and mouse carcasses.
+1 to this. I pulled an AC "kit" out of a wrecking yard car and the intake side of the evaporator was packed solid with dirt and leaves and feathers and everything else the blower sucked in. Took a good while to clean that mess up without damaging the fins.
Bam-bam, long time since we've had a long-distance car collaboration project! Thanks for the tips. I don't WANT to remove that core, and it's NOT leaking, so I'll 1) reflush it (with any chemicals???) and 2) think about air flow. I think it's hot enough--not great, but should be enough.
I buggered a cable at some point that controls the air flow (windshield, face, floor etc) so it's shorter now, and I don't have one of the options now (but this isn't a problem, really, b/c the directions for air flow that really matter, still work). I maybe could try to replace that cable to be sure it's working right, AND while I'm at it, check the temp dial cable to be sure it's all the way open when I have it at max hot. Same deal for the fan speed. Actually, that fan speed dial is starting to fail (doesn't always turn on--have to really wiggle it sometimes). It's a 'contact' thing, I think--anybody know? I'm sure it will be obvious when I pull it. I'll let you know, but if anybody has experience with re-furbing that gauge, let me know!
Bam, about that A/C. I've never had A/C in this car, but it has it. So last winter break, I pressure tested the A/C, seemed fine. Put a new drier in, and charged the thing, and damn if it's still not leaking right at the fittings by the firewall. I did (VERY carefully) have to re-tap a new thread size into the compressor for the high pressure lines to connect--it was a bear, and a pity that in the end, still had no A/C.:disturbed: So the Drier (was) new; I know it's instantly old the second you install/charge it. I live in a pretty dry place (not GA) and would like to think that I could get by w/o the A/c+defrost combo, but maybe not? I'll check clean the evap, but I don't have the tools/skills/time to build all new AC lines for this car, for the few days when it's hot. When I'm done and someone else on here has it, they can do that! Maybe it will move to GA, and then it will need AC.
Ok--I'll let you all know how it goes and what I find!
tips re:chemicals in the reflushing step?
tips on great insulated gloves and boots to get through the next few weeks? Sheesh, it's cold.
Thanks!
sharon
>-*a word of caution about those hoses*... If you want/need to remove the hoses from the heater core, first obtain new hoses, and then carefully slice the old ones with a razor and peel them off. All but one of the EF heater cores I ever had to replace were because some ham-fisted dummy twisted or mashed the copper core trying to get hoses off.
SACRIFICE THE HOSES TO SAVE THE CORE
more later,
the ham-fisted dummy
PM me an address and I'll tell Santa where your chimney is. When I scrap a wagon, I save the whole HVAC 'cluster'. Cables and all.
...but while we're talking about cooling systems and such, how old are your hoses? I mean ALL of them, even the little ones in the EACV-FITV loop. It's a very preventable failure cause, especially important for those of us who travel cross-country in 25 year-old cars. Doesn't bear on your current issue directly, but if you intend replacing coolant anyway, it's a golden opportunity to avoid paying roadside stupid tax later.
More later, back to work...
I hear you about replacing hoses. I think just about all my coolant and fuel line hoses are new now. I did have one explode just south of the ID/NV border to remind me about them. (on that one, when I re-bled the system, I 'ham-fisted' the stupid bleeder right off when I tightened it! Love having a good welder nearby-not pretty but it works! Don't over-tighten your coolant bleeder valve!!!).
I have a buku o rings for the AC system because the very first thing I did when trouble-shooting it, was to meticulously go through and replace every last one of them (and I bet the ones I pulled were original--oldddddd). So those were all new 11 months ago. For anyone doing o-rings, read below** A/C system still leaked--looked like the metal itself was leaking (UV tracer dye)? Is that possible? joints were A-OK w/ new rings.
**Replacing all your A/C o-rings tip: get the A/C diagram and different colored highlighters (one for each ring size) and highlight each o-ring on the paper with the correct color--you'll want this when you're in the garage and you think you've replaced them all. I had a whole mess of o-rings, that I measured and sorted in the right 3 or 4 sizes I needed for this car. I put them in little baggies, with a scrap of paper with the corresponding color/size. In the garage, I would replace all of one color/size ring, crossing it off on the diagram, until I finished the whole system. There are a lot of O-rings. Have fun and patience, but do get them all, or it will leak where you forget to replace one!
I still maintain that air flow is the bigger concern. Even if coolant flow was impeded a bit, the core would still be hot. Maybe even hotter? Have to be plumb stopped up to not work.
Follow the steps above, see if the outlet of the core is hot like the inlet.
So thus we commenced the replacing of the heater core. This, as most of you know. Involves finding 72.3 screws and clips that keep the entire dash together, unclipping every wiring harness (made of hard plastic that never really wanted to come apart,and surly not after 25 years of happily being together), finding all the stamped sharp sheet metal parts with tips of fingers and edges of knuckles, and dropping the steering column. We tried to keep track of every part, but I was more than thankful to have dad's backup cups of old Subaru crews and clips and such--they're all the same. We managed to not break much plastic, and got everything between the seats and the firewall OUT. As Bam suggested, we thought about airflow. My A/C Evap wasn't that clogged, no small animals or leaves, but since I have no intention of getting A/C in the car for as long as I have it. I unbolted that unit and removed it. I plugged the two holes through the firewall with two properly sized dowels. (Whoever gets this car next can easily remove them and get AC, if they wish).
New heater core install was quicker than the removal, mostly since order of dashboard operations was fresh. Core fit well (just a tiny bit of bending to make the two pipes line up just right). We got everything together, installing 'new-to-me' heater controls (hurray, I now get air flow in ALL of the positions), cleaning every dash part as we put it back, getting the heater hoses on (didn't buy pre-formed, just cut bulk hose to length), and refilling the coolant (remember to close your butterfly cock on the radiator before you refill--oops!). Started it up. Nothing seemed to leak. Let it warm up and hot dog if I don't have heat in my car. WhooHoo! No extra trips to the auto store. Nothing but Time and a lot of patience getting thing carefully apart and back together. No rocket science. Just 4 hours of flusing, and 16 hours of removal and reinstall. (I did re-greased my drinding speedo cable, scrubbed oily marks of the inside of the engine compartment, cleaned/topped off battery etc, every time I started to mentally loose it since it's a long, slow project.) I think of projects where you're under or squished into the car a lot like yoga; imagine auto-yoga class... "With a steady and relaxed gaze, reach your left hand up and behind your head and feel for the tiny clip that will make you bleed as soon as it releases (usually after 20 minutes), also causing crusty bits to fall directly into you eyes. Now with a calm and collected mind, reconnect it. Do this 17more times in slightly varying positions. Don't mind that your fingers, now slick with their own blood, can't really grip any clip/nut/tool, or that the tension in you back is enough to cripple and elephant. Soon you will be one with you car. When you finish, close your eyes and take a deep breath in, and out, and start you engine. When everything fires up, with no trouble-codes and the problem solved, you and your car have become more one."
Anyway--baffled by why my seemingly un-clogged heater core wasn't working (and we had plenty of air flow and the valves were working etc etc etc), we dad clamped that old core in the vise and took the hacksaw to it. There must have been a channel that was open, but every last bit that I could see, was gooped up with some gummy grey mess that the previous owner had used for a headgasket leak. If I ever see someone putting that stuff in an engine...sheesh. Is easier to change the engine than the heater. Figures--I blew the head on the engine the first day I drove it, replaced the head, eventually replaced the whole engine. And now the heater.
Low tonight is -18F and last night I drove 280 miles in snow and wind, temps well below 0F, and yet I was warm and the windows stayed clear. Love it. With skinny, tall studded tires, and good suspension, RT4WD, (and now a heater) this is the best winter car I've ever had.
Wearing flipflops while I drive in the winter. Cali meets Wyo.
Just had mine out to replace all the foam gaskets in the HVAC ducts. My heater blows nice and hot now. 135f at the center vent on a 40f day.