Exodus Posted November 18, 2014 Report Share Posted November 18, 2014 Info on car: 1997 Honda civic hatchback 1.6l 120k bone stock New headgasket, water pump, and timing belt done last summer. My wife called to tell me her civic over heated on the way to work this morning. Her commute is only about a mile and a half and it felt like 15 degrees outside this morning. Anyways, I stop over at her work to take the car out and I notice its low on antifreeze so I fill it up (I used 1/3 of the antifreeze container on it). I couldn't see any leaks at all, I drove the car around the block about 10 times and up and down 5th ave and I couldn't get the car to go past normal operating temperature. The only thing is, no heat comes out of the vents now. The car is all warmed up, but there is not one degree difference than if I had the car on cold.. Any Ideas? Anyone want to make some money and fix it? Quote Link to comment Share on other sites More sharing options...
Not Brian Posted November 18, 2014 Report Share Posted November 18, 2014 I'm guessing the thermostat may be stuck open. Quote Link to comment Share on other sites More sharing options...
Exodus Posted November 18, 2014 Author Report Share Posted November 18, 2014 I'm guessing the thermostat may be stuck open. Thats a possibility but even with that don't you think maybe some heat would have come out? We've been using the heat in her car everyday until today. Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted November 18, 2014 Report Share Posted November 18, 2014 Sounds like you have air in the system. I would run the car for a while to get it up to temperature and feel the upper and lower radiator hoses and see if there is a temperature difference (air bubbles possibly would not cause this, but it is a good way to check for a stuck closed thermostat). Quote Link to comment Share on other sites More sharing options...
Not Brian Posted November 18, 2014 Report Share Posted November 18, 2014 It blows cold air with the heat on right? Does it blow even colder air with the knob set to cool? Quote Link to comment Share on other sites More sharing options...
Exodus Posted November 18, 2014 Author Report Share Posted November 18, 2014 It blows cold air with the heat on right? Does it blow even colder air with the knob set to cool? Its about the same as far as I can tell. Ice cold. Quote Link to comment Share on other sites More sharing options...
bmwohio Posted November 18, 2014 Report Share Posted November 18, 2014 Yea, system needs bled. Not sure how that's done on a Honda, but you need to bleed and get all the air out of the system. Sometimes this requires raising the front end of the car so that gravity will help too. The car will need to warm up and run for at least 20 mins to get the pressure built up and the tstat open. Quote Link to comment Share on other sites More sharing options...
Geeto67 Posted November 18, 2014 Report Share Posted November 18, 2014 if it is air in the system it is probably stuck in the heater core. drive the car with the heat blasting for 30 minutes and that should work the stuck air bubbles loose. Feel around the carpet for wet spots. If the heater core went bad and started leaking then of course you wouldn't get heat because the hot coolant is escaping somewhere. A blocked heater core would also explain the overheating as it acts similar to a stuck thermostat in keeping the coolant from circulating. Quote Link to comment Share on other sites More sharing options...
Not Brian Posted November 18, 2014 Report Share Posted November 18, 2014 Keep the radiator cap off while it's warming up.. that gets some bubbles out. Quote Link to comment Share on other sites More sharing options...
Exodus Posted November 18, 2014 Author Report Share Posted November 18, 2014 She just drove home and now the heat is working just fine. The upper radiator hose is warm, but the lower radiator hose that goes to the thermostat is cold. I take it that the thermostat is stuck closed? Quote Link to comment Share on other sites More sharing options...
Geeto67 Posted November 19, 2014 Report Share Posted November 19, 2014 lower rad hose is cold coolant going into engine, upper is hot coolant going into radiator (unless you have a reverse flow engine that cools heads first). If thermostat is stuck the upper would be cold. Since it was extra cold today I would expect the lower to feel "cold", so it sounds normal to me. BTW, what condition is the coolant in? I just had to flush radiator in my jeep because the coolant was rusty and causing the thermostat to stick. Quote Link to comment Share on other sites More sharing options...
Not Brian Posted November 19, 2014 Report Share Posted November 19, 2014 She just drove home and now the heat is working just fine. The upper radiator hose is warm, but the lower radiator hose that goes to the thermostat is cold. I take it that the thermostat is stuck closed? No the bottom hose is supposed to be cold. There may have been a piece of shit stuck somewhere. I would flush and fill if I were you. Quote Link to comment Share on other sites More sharing options...
Rocky31186 Posted November 19, 2014 Report Share Posted November 19, 2014 With these Temps I see a lot of water in cooling systems freezing. Blocking coolant flow and over heating. My guess is radiator had a frozen section, overheated and spit some out, you topped off leaving an air pocket which worked it's way out. If it wasn't 15 degrees yesterday I wouldn't think that but with these cold Temps I've seen a lot of issues if 50/50 mix is incorrect Quote Link to comment Share on other sites More sharing options...
zeitgeist57 Posted November 19, 2014 Report Share Posted November 19, 2014 I have nothing to contribute, aside from saying that Rocky and Nickey are pretty much the greatest, most accurate internet mechanics I've ever listened to. Freezing makes sense to me if your dilution of water/coolant was too heavy on the water side. Come to think of it, I've got a ton of water in Cleetus' radiator from the summer....gaddammit... Quote Link to comment Share on other sites More sharing options...
Exodus Posted November 19, 2014 Author Report Share Posted November 19, 2014 Thanks guys. I'll flush it this weekend and see how that works out. From what I'm hearing some of the coolant may have been frozen somewhere. Too bad it's damn 15 degrees out. Quote Link to comment Share on other sites More sharing options...
koolrayz Posted November 19, 2014 Report Share Posted November 19, 2014 With these Temps I see a lot of water in cooling systems freezing. Blocking coolant flow and over heating. My guess is radiator had a frozen section, overheated and spit some out, you topped off leaving an air pocket which worked it's way out. If it wasn't 15 degrees yesterday I wouldn't think that but with these cold Temps I've seen a lot of issues if 50/50 mix is incorrect This^^^^^^ Saw it many times when I lived in Wyoming Quote Link to comment Share on other sites More sharing options...
unfunnyryan Posted November 19, 2014 Report Share Posted November 19, 2014 I'd still put money on thermostat. Just did it on a friends car who had pretty much exact same symptoms, overheated, etc. last week. It's $10 just replace it anyways when flushing the coolant. Quote Link to comment Share on other sites More sharing options...
coltboostin Posted November 20, 2014 Report Share Posted November 20, 2014 I'm guessing the thermostat may be stuck open. I'd say stuck closed. Stuck open in this weather, it will never heat up. Quote Link to comment Share on other sites More sharing options...
Exodus Posted November 27, 2014 Author Report Share Posted November 27, 2014 turns out to be a frozen radiator. Thanks Everyone! Quote Link to comment Share on other sites More sharing options...
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