Heating Nightmare

Wreckless Hype

Registered VIP
5+ Year Member
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 last night in 5 hours of snow storm at 35mph with no heat and no defrosters, etc, was a blast.

This morning, 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.

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.

Wreckless Hype

Registered VIP
5+ Year Member
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.


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.


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