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Hi there everyone, I'm now a Honda owner after a long period of not having one. I picked up a 04 Honda Civic EX Coupe 5 speed yesterday from a dealership. It has 203,000 miles on it. Last night as I was driving around town, I noticed that I don't appear to have any heat when the car is idling, like at red lights and stuff. It blows cold air. I've been looking around and I'm seeing a lot of head gaskets. It seems like when I'm coasting in neutral, it also blows cold air. Whenever the RPMs are higher then heat comes out and works really well. After getting off the highway in 5th, it might take a few minutes, but eventually I'll come up to a stop sign or red light and it'll be blowing cold air. Do any of these symptoms sound similar to anything anyone has experienced? I'm REALLY hoping it's not a head gasket. I JUST bought the car.
You can try isolating the heater core and flushing it separately from the rest of the cooling system. It's rather common that owner's use cheap store-bought coolant to fill their systems, and when mixed with Honda Type-2 coolant it can break down and turn into a more gelatinous sludge; clogging the heater core. Always use Type-2, if you ask me. I even run Type-2 in my 2000 F-350. It just works better at the task of cooling.
Top off both the radiator and reservoir with coolant, open the heater valve on the firewall wide open, and thoroughly bleed the cooling system. Then go from there.
Thanks everyone for your responses. I ended up getting some cheap coolant and topping off the radiator (did not realize I needed a specific type). I burped the system as best I could. When I drove down the freeway it was putting out some pretty serious heat, however when I got to my destination, I let it idle and the temp coming out of the vents dropped. Not as bad as before, but not as strong as the freeway. I noticed that the engine temp went down to a little above 1/4. Still ok heat coming out of the vents. I opened the hood. Top radiator hose is firm and warm/hot. I drove home and the car got back to temperature and hot air coming out of the vents.
Once I got it home I let it idle for probably 10-20 minutes. Initially the engine temp went down to 1/4 and then rose back up to middle. Initially I had warm air coming out of the vents, but after sitting for awhile the car got back to middle temp and I had hot air coming out like I was going down the free way, but I was just sitting still.
No weird smells or anything coming from the exhaust. Is it possible maybe the cooling system just needs to be "burped" every once in awhile. The ambient temperature in MN today was like 1 degree F. Is it possible those little engines have a hard time keeping up in the extreme cold like this? My Dad has a similar car and says it kind of does this too.
What do you think? Do you think the dealership would give me my money back? I thought that once you bought an as-is used car you were kind of stuck with it?
You didn't mention "as-is used car" previously. I highly doubt they'll honor much if that is the case. As for your car's scenario, you shouldn't see the temperature of the heat in the vents drop unless the car sat for a while. Idling the car should actually improve interior heat, unless you're in a far more extreme climate (like -30F or lower).
I'd definitely give the cooling system a thorough flush and replacing the thermostat while you're at it.
Sounds like the cooling system still has an air pocket. Bleeding is done with the radiator cap loose and heater set to max to push air out of the heater core.
The first time I let it idle the engine temp dropped. However the second time I let it idle, initially the temp dropped and then came back up, resulting in stronger heat out of the vents. I guess my biggest concern is the head gasket. I had a Subaru Legacy 2.5GT, notorious for their head gasket issues. That was an extremely expensive repair.
It does seem like I probably still have an air bubble. This system is kind of different for "burping" than I've dealt with in the past. What is the process? I should be on an incline, correct? Then with the radiator cap off, start the car with the heat on max. Top off radiator? How long should I let it run. I figure you don't want it to get too hot otherwise it's going to spray everywhere from the pressure? I just don't want to introduce air back into the system.
Then, you'll want to be on an incline with the radiator cap at the highest elevation. Fill the radiator and then have about 1/3 of the burping funnel filled. Depending on the temperature, you'll need to run the car for a bit. You want to see the temperature gauge hit operating temp., so you could be there for a bit. I would advise against hard revving, though. You may end up with a geyser if you try that.
Thank you for the advice! I was reading a few reviews of the product and it seems like that's just the way these "newer" cars are with their cooling systems. I need this tool to properly get the air out of the system. My biggest question is, once the air is out of the system, how do you remove the tool and put the cap back on the radiator without introducing more air into the system (and not burn yourself)?
You have the very top of the radiator, then about half-way down the neck you have the hole for the overflow. I'm assuming you want fluid above that hole so that you don't create an air bubble. How do you make sure that when you put the cap on the radiator you don't just jam a huge bubble down there?
After setting the heater to MAX heat and topping off the coolant in the radiator and reservoir, the diagram below shows the service manual procedure for bleeding. Having the car on an incline with the front higher than the rear may help. The procedure may take 20 minutes or more because the radiator fan must turn on twice.
Awesome, thanks a ton! That helps a lot! I'm going to see if I can get the dealership I bought it from to do a coolant flush and a heater core flush for free. We'll see how well that turns out. I'd do it myself (have done on other cars), but with as cold as it is, I'd prefer not to wreck anything.
Well, I tried and failed. I ended up taking it to the dealership I bought it from. They're going to take a look at it and "heavily discount" any services it needs. I don't know why I sometimes think I'm an exception (this happened with my Subaru too), but I'm pretty sure my car has the head gasket issue too. Upon reading all the people who tried everything under the sun in that other thread only to find out they had the head gasket issue. When I was driving it there last night, it blew crazy hot heat on the freeway, then I coasted up the ramp to a stoplight and it started blowing icy cold. I pulled into the service bay and it was still blowing cool, luckily the service adviser was able to see it in action. I got a quote from one independent guy who wants $1500 for the head gasket (w/o head work), timing belt and water pump. The Honda dealership quoted me $1800, so $1500 seems kind of high to me.
If I'm going to replace a head gasket, it would be silly not to replace the timing belt and water pump, wouldn't it? Especially when you've got half the engine torn apart anyway? I might just see what they'll give me for a trade-in. You'd hope it would be close to what I paid, since I've owned it less than a week. Doubtful...
If you change the headgasket, spend 50$ more to get a water pump and a timing belt for sure... The parts are not expensive; the labor is. ''Kill two birds with one stone''.
There's no ''2 week'' grace period where you live? We have a law here that obligates the sellers to refund any purchase within the 14 first days. I wouldn't break my back in half for this; I would return the car.
Unfortunately, I don't believe Minnesota has that. The car has over 200,000 miles and I paid around $3000 for it including tax, title, license, etc. I received a call back from the dealership advising me to flush the heater core. I approved the work and received another call back that says the heater core needs to be replaced because the flush didn't resolve the issue and there could be a blockage. Would that make sense? If coolant is not circulating through the core, and just sitting there being blocked, would that explain the hot air while driving and cool air at idle/stoplights? Could it be that I actually don't have a head gasket issue?
Are you experiencing any overflow issue with the coolant?
i'm having the same problem on my 2004 LX and my overflow is full. Sounds like a blown head gasket to me (my car...)
Radiator and A/C fans doesn't kick in as well... I'll be replacing my thermostat tomorrow and do a complete coolant flush / heater core flush and see how it goes...
It could also be a faulty water pump. If it's worn out, it won't ''suck'' enough coolant on idling but it will as soon as your car would rev since the pump is activated by the timing belt (which is activated by the engine itself...)
I'm also trying to figure it out and it's a pain in the a**
That's the weird part, in my particular case I am not experiencing the overflow issue that would indicate a blown head gasket (I had this issue with my Subaru 2.5GT). However, from reading that other thread, I'm convinced it's still a blown head gasket. My car is due for a timing belt and water pump replacement in about 20,000 miles, so it could very well be a bad water pump.
Yours sounds suspicious of the head gasket. However, replacing the easy stuff first (thermostat, etc.) is a good plan. In that other thread they mentioned replacing a temp sensor or something along with the thermostat otherwise it doesn't do a bit of good. Maybe that will fix your fan issue as well?
Look at me acting what I'm talking about, you've probably thought of all of this already... If I lived anywhere near you I'd totally help you swap out the head gasket and such just to get some experience on how it's done.
I dont know if the hondas have the same type of system. But with my camaro's the easiest way to check if the headgasket was bad was to do an oil change. If the oil was cloudy or milky/foamy, headgasket needs replaced. Its a quick and easy test and, you get your oil changed if it isnt a bad head gasket.
As far as flushing your heater core. I did mine an easy way of disconnecting the two lines that run to the heater core. I then attached a "water balloon valve" no idea what they are really called, but i used this
I connected this to one end of the inlet for the heater core, and a tube from the other to a 2 liter bottle to catch anything that came out, i then turned the hose on and let it flush out anything in there.
Mine improved for a day or two after adding additional coolant and kind of "burping" the system, but it got really bad once I ended up finally taking it back to the dealership. To be honest, I'm not entirely sure how they determined it was a faulty head gasket. I'm thinking they probably did some sort of compression test or maybe used some dye. When I bought the car 2 weeks ago, it had just had a fresh oil change (and probably less than 5 miles on it), so I wasn't really able to see and swirling or milkshake. If it does have a head gasket leak, I don't think it's that bad (although no heat in the MN winter is pretty harsh). If it wasn't that, and it wasn't a heater core, then I don't know what it is/was. Ultimately, I think they're going to take the car back and try and find me something different. They've had it longer than I have, but I kind of miss it. It was kind of sporty (2 door coupe with the spoiler), got good gas mileage, and I loved the color. By far the coolest car I've ever owned.
I'm hoping you have some good news on yours though, thecca!
Overflow level keeps rising. My headgasket is probably worn out, I don't see what else it could be. It doesn't burn any coolant though (no white smoke). I could probably thought it and keep adding coolant once a month in the radiator, but the gasket will end up blowing soon or later and I don't want that to happen on the road...
02-22-2015, 03:03 AM
04 Civic No Heat at Idle
