Honda Civic 2000-2005 Problems
Since fall I have had a progressively worsening coolant leak. The problem is, I and two mechanics cannot find it.
They've replaced the thermostat, the hoses connecting the radiator and the radiator cap. No difference. They've tested the oil for any traces of coolant. No traces. They've let the engine cool for about 5 hours and pressure tested it. Nothing apparent.
The leak loses antifreeze over months but seems to be speeding up. I've noticed the heater stops working a few days before the engine begins to overheat (so I put in coolant). There aren't any puddles under the car.
Leak sealant seems to have helped the problem before, but I am not sure it is now.
The overheating also seems to happen in the pauses after long trips. I took a 70 mile trip today, and then it began overheating when I got off the expressway. I had checked the antifreeze levels before I left but haven't checked after because it is too dark.
There was something new today. I also smelled a bit of a chemical smell towards the end of the trip but not during it. Of course, I also went through an industrial area.
There is also no apparent wet spot inside the car and on the floor under the dash, where a leaking heater core would create that mess.
Any suggestions?
They've replaced the thermostat, the hoses connecting the radiator and the radiator cap. No difference. They've tested the oil for any traces of coolant. No traces. They've let the engine cool for about 5 hours and pressure tested it. Nothing apparent.
The leak loses antifreeze over months but seems to be speeding up. I've noticed the heater stops working a few days before the engine begins to overheat (so I put in coolant). There aren't any puddles under the car.
Leak sealant seems to have helped the problem before, but I am not sure it is now.
The overheating also seems to happen in the pauses after long trips. I took a 70 mile trip today, and then it began overheating when I got off the expressway. I had checked the antifreeze levels before I left but haven't checked after because it is too dark.
There was something new today. I also smelled a bit of a chemical smell towards the end of the trip but not during it. Of course, I also went through an industrial area.
There is also no apparent wet spot inside the car and on the floor under the dash, where a leaking heater core would create that mess.
Any suggestions?
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Also replaced the thermostat, got the hoses checked, changed cap, nothing worked.. A buddy looked it up on some software he has for cars and it had like 7 hits for a cracked head gasket.. Then about a month later my radiator blew as I was pulling into my driveway.. Ordered a new one, just got it put in. I still don't know if it fixed the problem because when i started it after getting the radiator put in, my instrument cluster went out... No luck.. But I will let you know after I figure out the instrument cluster...
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Thanks!
Sorry to bother you. I was wondering if you ever located that leak. I have a 2003 honda civic and I and 2 other mechanics cannot locate the leak. I can get about 120 miles out of it till it overheats/runs out of coolant. I changed the radiator cap because the reservoir was filling up and I changed the thermostat just because.
The radiator is a three-piece assembly with plastic top and bottom tanks held on by crimped metal tabs. It is likely starting to separate because of vibration and fatigue. Look around for a one-piece radiator with a good warranty and see about replacing it.
My 2002 Civic EX with 175k miles is behaving the same as yours. I've only replaced the thermostat & added coolant. Worked great for one week, then it was overheating during a 30 mile drive. Towed car to trusted mechanic & he couldn't find any problems. He added coolant from loss due to overheat. Burped the system in 65degree shop for 40 minutes. Civic worked just fine for one week. Then during a 50 mile drive....overheating again. PLEASE let me know if you figure out this problem.
I would appreciate an email direct: jason_labine@yahoo.com
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If the car goes above 60, that is where there is most fluid loss. There is NO dripping at this point or coming through the radiator cap. There is no white smoke. There is no water in the oil. There is no water in the cylinders. The car drives smoothly as it did when I bought it. At this point, I'd just like to know what it is.
Any ideas appreciated.
Did anyone ever get a answer to this? I have the same problem but im losing oil after doing the haed gasket the mech did the head twice and it still has the same problem and its getting worse.... Anybody .lol
Had the same problem with my 03 civic ex. The mechanic found that a plug that connects to the air box area was loose and plugged back in. He said this would happen because it was loose and said something like the thermostat would not be able to work properly by not being able to read what the sensor is telling it to do. I'm not a mechanic so my explanation isn't great. Try some the plugs that are around the air filter system. That should take care of the problem. Good luck.
My explanation was for the problem with the heat initially coming out warm from the vent but then coming out cold afterwards while the thermostat is reading a normal temp and no leaks.
My 2003 has 260378 miles on it and I started having the same probem. I have changed the water pump, themostat, hoses, radiator and the radiator being the last it went a week before overheating again. I find it hard to believe the mechanics can't find what's wrong. I drive 35 miles one way to work and I have to add fluid in the morning before I leave and in the evening before going home and can't find no leaks and the oil is clean.
Thermostat changed twice, hoses done, cap replaced, fans tested, rad replaced, a gas test done resulting in engine being changed. Just when I fianlly thought we solved the problem. Overheating again with rad fluid spilling everywhere. Getting rather discouraged. I have always been a Honda fan. I'm beginning to change my mind about that. Any suggestions are welcome.
I reconnected the hose and put a zip tie on it to make sure it doesn't come off again, then bled the cooling system. It's very important to bleed the cooling system on this car as it does not like air in the system at all. Some cars have bleeder valves at the top of the engine somewhere but I don't think this car does. So to bleed it, do this:
1. Wait for the engine to cool down completely
2. If that little overflow hose is disconnected, connect it back up again
3. Remove the radiator cap
4. Top off the radiator with coolant. Leave the radiator cap off
5. Start the engine and turn the heater on full
6. Monitor the coolant level as the engine runs. As bubbles escape and the level of coolant drops, keep topping it off. It might take 15 minutes or so before all the air escapes from the system and the coolant level stays at the top.
7. Put the radiator cap back on and check the overflow reservoir for proper level.
That fixed my girlfriend's problem.
One more thing to check if the above is not your issue - there is a molded coolant line running from the top left side of the engine around the back to the air intake area. There's two of those molded lines in the intake area. They can develop pinhole leaks. To check them you'll have to remove the battery, the air intake resonator box and the air filter housing. Search Youtube for videos showing how to do this.
Then we forgot it happened at all.
That was the same day we got our oil changed so we made that mini roadtrip.
And now there are dark spots all over the driveway and not in just one isolated spot, but 4-6 different spots, and looks like a few different shades and of dark brownish, amber, or possibly they have hints of oranges and reds and all different sized puddles and coming from all over under the hood. i have no idea which fluid (s) these are, even after the smell and feel tests. (Partly because i have no frame of reference on what is what...but also they do all look similar and also different...)
Any help offered is much appreciated because i currently have no money to bring it to a shop even for a quick diagnostic, if they charge for those....???
Need haaalp!!
I cant lose this car right now, i mean it is NOT optional so please advise me what to do here, anyone ? I dont think i can pay mechanics in just kind words and high five emojis, so any helpful tips are welcome...and needed!
Thanks again!
You might spread newspaper out, drive on it and then "read" the papers in the morning. The colors should be distinct on white newspaper and you can tell where the leak dripped from by it's position on the paper relative to the length of your car.
Maybe you could borrow a set of ramps and scrunch under there and tighten up a few things?
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