Wreckless Hype

Have been doing A LOT of research, looking at what everyone has and I'm not sure if I need to replace everything or what.

Background story: Never tried the heat really when I bought it (in June), could have been blowing ambient air and I would have been like, "Yep! Works." Driving two nights ago in 5 hours of snow storm at 35mph with no heat and no defrosters, etc, was a blast.

Yesterday, I had a ton of condensation inside, which I've never seen before. Could have had something to do with all the snow inside, whatever. The floor is damp where there was snow (driver's side) and passenger side had condensation (little bit) under the dashboard, on the blower. This morning there is condensation inside again.

What I checked:
- The temperature slider gets about 90% over to the hot side but never hits the end. If you push it, it kinda pulls back to that 90% spot. I tried adjusting it from the valve in the engine bay, same thing.
- Radiator is topped off, could probably be flushed, I'll admit.
- Hose going to the valve to the hose going inside, both sides of the valve are warm. Hose coming out of the firewall to the little block with the hose to the manifold and the bottom of the radiator is cold. The hose going to the bottom of the radiator is also cold, as well as the hose going to the bottom of the intake manifold. All 3 of the hoses coming from that little block with the sensor and ground on it are cold. (Car was running with heat on blast for about 20 minutes AFTER reaching normal temp)
- Yes, the car reaches normal temp (hair below half on temp gauge)

Where do I go from here? Can a flush resolve all of these issues? Does the valve need to be replaced because of the temp setting shorting itself on the hotside?

Anything I might have missed or any other info I need to post, let me know.

Thanks in advance.

MindBomber

Do you know when the last time the coolant was changed?

Wreckless Hype

Bought the car in May, never got around to it... Changing it in about 5 minutes. Will update.

gearbox

iTrader: (95)

if the lower radiator hose is cold, your thermostat isnt working. if the lower firewall heater hose is cold, the heater core is clogged. all of the coolant hoses should be hot after a long drive if the car is warmed up and heater turned on. since you are doing a coolant change, its the perfect time to swap out the thermostat with a new honda part. see if that fixes it. if the firewall heater hose return is still cold, its likely the heater core not passing coolant.

im surprised you havent overheated yet because if the lower hose is cold, you basically have no working radiator.

Wreckless Hype

So you may be right. I drained the coolant, there was maybe a quart that came out when I dropped the lower radiator hose. It was grimy to say the least. I dumped in a bunch of vinegar to clean it out, started it to get it circulating and noticed the bottom hose was again, doing nothing. The car hit normal temp and just sat, heat blasting.

Car off, pulling hoses:
Hose to the heater valve seemed normal, definitely some fluid in there. Pulled the hose from the second heater core line (cold line, if you're looking at the front end, it's on the right.) and old fluid came out so no new fluid is getting there. I pulled the entire hose off, and used it to route from the block where the thermostat is to drain the fluids. When I left that hose, took the radiator cap off, old fluid came rushing out.

I like your theory about the no working thermostat. It seems no water is getting past. The line from the radiator to the block is hot. From the top rear of the manifold to the thermostat block (what ever you call that) is hot. The line to the heater valve and after the valve is hot (working valve). The line from the core to the motor is cold.

gearbox

iTrader: (95)

you might try flushing the heater core with pressurized water thru the firewall hoses and hope whatever junk is inside comes out. changing the heater core in the dash is a huge pain and not something you want to do except as a last resort. thermostat is easy now that you took everything apart, just be sure to use the honda oem part. aftermarkets have a high fail rate. and even when working, they do not open enough. try and use the honda coolant too if possible, it will save you from all these problems in the future. it has much better protection than your average coolant. or you could use the zerex import vehicle coolant if its easier to find.

gearbox

iTrader: (95)

taken from another forum:

Test the corrosion protection of coolant. With a digital voltmeter, put one probe in the cool coolant in the radiator neck (not touching metal). Put the other probe on the battery negative post. If you read 0.1 volts DC to 0.3 VDC, you're good. If you read 0.5 VDC or more, your coolant had depleted corrosion inhibitors and is due (or overdue) for a change. You're reading the voltage generated by the galvanic action of the dissimilar metals and the electrolyte (the coolant).

Wreckless Hype

Ran to the local autozone as Honda was out of thermostats. Just using a Duralast so I can check that it will open (lower hose get warm) which it now does.

I ran through a cycle of only vinegar and let it run at normal temp for about 20 minutes. I drained it from the lower radiator hose and got all my hot vinegar smell. I pulled the hose off the core return (connects just on the other side of the thermostat form lower raddy hose) angled it down and pulled the raddy cap to drain that. I don't remember having to do this (2 drain points) on my previous, 96 Civic which used a GSR motor instead (Relevance?)

Drained vinegar, ran 3 cycles of distilled water through, removed a lot, A LOT of crap from the cooling system.

Now:

Both hoses to the heating core do NOT get warm at all, just warm from being near other warm hoses. I checked before and after the valve, and the return hose, all same temperate. From the thermostat block there to the back of the manifold gets warm, upper and lower radiator hoses are warm. So for now, coolant is at least flowing (not sure what it's been doing for 16'000 miles...) But it does not seem to be hitting the core.

I pulled the hose from the front of the valve and it didn't seem much was going through. Maybe I can get someone to do a pressurized flush as I can't...

gearbox

iTrader: (95)

yeah it sounds more serious than just a plugged heater core. and judging by what you say came out, imagine what is still stuck inside the tiny passages. i know vinegar is pretty good, but you may want to try getting a flush kit from the store which comes with a special chemical to really get the junk out. a water flush from the garden hose is also a good idea afterwards, given the circumstance. just be sure that you flush it out a few more times with distilled water (its like $1 a gallon at walmart). then add the coolant and see what happens after verifying that water is reaching the firewall hoses.

Wreckless Hype

I started with a gallon of vinegar and then about 4 gallons of distilled water. Now there's just 50/50 in it for now. I'm going to find a local guy and have him force flush it. I live with only on street parking so a garden hose is a no no. Not a big deal I guess, knowing what I'm working with. Will update. Thanks for the help so far!

lazlong

Great video of a heater core flush with CLR. You also need compressed air with a rubber tipped air gun.

[autostream]http://autostream.com/ibcivicforums/?page_type=firebirdplayerthumbnail&framepage=104&t ransactionid=1320102717-6619010220&posted_by=lazlong_www.civicforums.com&y outube_video_id=dcL_0TWeZJY[/autostream]

Wreckless Hype

Not sure if this confirms or rules anything out BUT, I was driving to the liquor story (damn car) and decided for the S & G factor to just flip the heat from off to 4 on the highest heat setting (remember it won't go all the way right for some reason). The car was already warm from adding coolant and was about 10 minutes into driving. Low and behold a blast of warm air rushes out and I about **** my pants. Within about 20 seconds, it had cooled all the way down to slightly over ambient using the from outside setting, not recirculate from within cabin. Weird?

gearbox

iTrader: (95)

its possible a bit of hot water went into the core. i mean the junk and stuff can move around as youre driving and as the water is trying to get thru. its just a fluke and i dont think you will get any actual hot air til you flush the system good. i would also have them do what lazlong posted about the heater core separately because just doing a power flush of the cooling system will not do anything for the clogged core.

Wreckless Hype

Yea, just thought it interesting and I should share. Kinda what I was thinking too. I'll find a place and let you guys know how I make out.

Wreckless Hype

Took me two weeks, had some crap to do on my only days off but it SEEMS like it's resolved.

Ran a garden house out to the street, because it's cheaper to do it myself. Pulled both heater core hoses off, plugged up the holes on the block to stop leakage. I put the garden hose right on the heater control valve and unkinked the hose. Water shot back at me, it was awesome. Almost nothing but a very small drizzle from the other side. I made sure the door was open, seems clogged, yep.

Since I had the OEM jack out, I used one of the crank pieces to lightly insert into the heater control valve and felt a little of resistance at some point while still going in. Pulled it out, weird brown mud looking crap on the end...

I put the hose on the other side of the heater core, held on tight and let it rip. About a second later, brown *** water comes shooting out the valve and I let it go until it was clear (bout 20 seconds) and let it go some more after that. Connected everything up, refilled coolant with anything I might have lost and started it up.

As it gets to temperature, I'm refilling the coolant, heat on blast and I begin to feel the heavenly warmth of the HVAC system. I switched it to cold, hit AC, instantly switched to freezing air (didn't know my AC worked!), switched back to hot, warm air. I switched it back and forth from cabin air to outside air and noticed the cabin air was a little warmer as I've always seen.

Well after the car was running for a little while, cabin was pretty toasty, I noticed the lower radiator hose was still cold (both heater core hoses were warm) which means I need to get to Honda and get me a new thermostat, stat.

Thank you guys much for the help!

gearbox

iTrader: (95)

glad you figured in out. another member suggested pouring CLR (yes that stuff) into the heater core and letting it eat up whatever scale is in there. then flushing with water to really get the junk out. i think after the thermostat all your problems should be solved.

lazlong

^^ Actually, I got it from Eric the car guy. It's in the video link I posted.

TotalPackage

My 1997 civic:

• Hose on top is hot
• Bottom is cold
• Heater control valve hose is hot
• Outlet is hot (not as hot as inlet) at firewall

I flushed with water and air. I also used CLR, but only could get 8 or less ounces in; not sure about that issue.

based on the threads, I will change my thermostat, even though it shows normal operating temp on the idiot-guage.

Started to tear down the dash for the heater core, but will change the thermostat first - I was told that it is not the thermostat due to it showing normal range on the idiot-guage.

MrDobin

Eric the car guy is awesome. helps a ton with flushes etc. And some of the stupid idle issues ya may run into

TotalPackage

I did already flush. Didn't appear to help. Is there an online manual for 97. ?

TotalPackage

I am currently taking the dashboard off.

04 Honda Civic

iTrader: (2)

I suspect that someone ran a "Radiator fix" product through that car. What does the stuff look like? If it looks similar to the picture posted above that is the case. Aluminum just doesnt throw chunks of rust into the motor.

Before you go about ripping your dash apart buy a coolant flush product like gearbox said and use it.
Use it EXACTLY how it says to in the directions. Then flush with a hose.

Pulling your heater core and replacing is pointless because your only going to have that stuff floating around once the new heater core is in.

I once flushed my friends legend out about 4-5 times before he got his coolant semi clean, and even after that it was still brown.

TotalPackage

I did run the CLr through it already. and it was uneffective. I did run barr's leak through in the summer.

Just took dash off, I will flush prior to starting this one up. how do you flush?

04 Honda Civic

iTrader: (2)

Use the link lazlong posted with the Eric the car guy video. He is very informative about Hondas.

TotalPackage

I have ran pressurized water, then pressurized air, then started to pour the CLR into one of the hoses going to firewall. I could only put, maybe, 6 - 8 ounces of the CLR in. And that is after I blew the core with air!

I checked the valve, then re-filled the radiator; I blew the core with water, then re-filled the radiator; then I blew the core with air, used the CLR overnight, then flushed with water, blew it with air, then refilled the radiator again. So I have refilled with fresh anti-freeze 3 times. Would that count as 3 flushes?

04 Honda Civic

iTrader: (2)

Where you live does it drop below freezing? Best thing to do is put the cleaning product made by prestone and top off with regular water and then drive it for a few days. Obviously you can not do this if where you live goes below freezing as you WILL crack the block.

TotalPackage

Ohio - so it drops below. Is it possible to use the flush-stuff, run it for an hour with water, then dump it out and put in antifreeze the same day?

04 Honda Civic

iTrader: (2)

Yea, just generally it works better if you run it for a day or two. I had great results using the prestone stuff make sure you do it properly. (Make sure your heat **** is set all the way to the hottest setting) Its important to run the heat at highest setting to break up all that gunk in the heater core. Good luck let us know what happens.

TotalPackage

thanks, '04...just pulled dashboard and trying to get heater unit off...this is harder than it appears.

TotalPackage

It was the heater core. All is hot for the daughter! What a pain in the ****.