Question about 2003 Honda Civic

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2003 honda civic over heating

Well my civic (2003) is over heating and its not the therm. its not the rad cap. and its not the head gasket. I had everything looked at. Some people thought maybe it could have air in it some where but we did try to push it out does any one know what could be going on??? Please help me

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  • danson0613 Jul 18, 2008

    03 civic overheating, replaced thermostat with an OE thermostat, replaced radiator cap, trying to figure out if the temp switch is bad, sometimes the fans come on when it should and sometimes the temp will be over the half way point and they wont be on. Checked the relays and they are good. Plus when ever I turn the ac on both fans kick on and stay on, even when the engine is completely cold, not sure if thats normal either. any info would be good, oh and its not a head gasket, no oil found in the coolant fluid.

  • blazenllc Sep 05, 2008

    I have a honda civic and I have changed the therm/ radiator/ sensors/ head gasket. Car still over heats after 20 minutes of driving. What do I do?

  • Lockeibew683 Sep 09, 2008

    I have a 2003 Honda Civic EX and I am having problems with it overheating. It will get hot then cool down and it has no pattern to it. Most of the time running the heater will cool it down, but sometimes it's cold air blowing out. My father and I thought that it had an air bubble in the cooling system, But it has not worked its way out and it's been three weeks. I have replaced the thermostat and didn't work. A good friend of mine works for Honda in service and he said it is probably my cooling fan switch. He also said if that doesn't fix it, it could be the head gasket. If anyone has had the same problem and has fixed it, Let me know @ Thank You, Chris.

  • Anonymous Oct 27, 2008

    I have a 2003 Honda Civic EX and I am having problems with it overheating. , I have replaced the thermostat and didn't work. 

  • jmcburne Dec 02, 2008

    I am having the same problem at 103,000 miles. I was on a long drive this past weekend and noticed the heater kicked off and started blowing cold air when we got stuck in traffic. The temp gauge started climing and the coolant was low. We had it looked at - thinking it was a thermostadt or a fan. Both checked out ok once they tooped off the coolant- leaving the head gasket as the most likely culpret. I was quoted $1100 to replace the head gasket at a Honda Dealership in Frederick, MD and an additional $395 to change the timing belt. Seemed a bit high. I have recently learned that it is recomended to change the water pump, timing belt, and therostadt if you are changing the head gasket because they all rely on each other's functioning and they are all such big labor jobs when done separately. Does anyone have advice?!?! But for the record my car had the same symptoms as the above discussed.

  • Schooshbag Dec 17, 2008

    everything stated above is exactly whats wrong with my car...the head gasket was mentioned as something that could be wrong but im hoping its not. If anyone has any other explanation i would love it. I already replaced the therm and has a radiator flush along and my fans do not have any problems kicking. everything else on the car is up to date. The main thing i have noticed is when i turn on my heating it used to give some hot air and then just blows straight cold air. When i get my car up to around 60 miles an hour it gives me hot air again. Then when i hit the brakes and slow down coming to a red light the guage cools down. But then cold air comes back out like crazy and as said there is no complete pattern to it.

  • Anonymous Jan 04, 2009

    mine does the same thing but only randomly and very occasionally. i replaced the t-stat, flushed and refilled the rad, and am still having the problem occasionally.... any ideas?

  • skytrubilla Jan 05, 2009

    Yes well to let you all know the problem is fixed in my 03 honda after putting $1,200 in to it. It was air in the rad. and it warped the head. But it is running strong now!!!! Yeah!!!

  • dadzi Feb 09, 2009

    same problem here. '03 civic, last september it was overheating -- dealership said thermostat tubes so they replaced that (around $400 total). then yesterday it overheated again, today they say blown head gasket. all the heating fluctuations described by the others, losing heat when idling, it comes right back when going down the road. i was quoted about $1600 or so (they were pushing some other work to be done to a total amount of over $2000 so this is an estimate). i just paid this thing off and i'm not sure if i want to put serious money into it since it has this history of overheating. i'm thinking of just getting rid of it and starting over. then again the guy at the dealership said he's seen cars go another 100K miles with a blown head gasket. btw i have no real loyalty to this car or to honda for that matter.

  • jamesedwards Feb 26, 2009

    Samain. Drove car around and gauge got hot then went back down but no heat at alle problem here also, my son has a 1995 Honda Civic 1.6L and it ran fine then all of a sudden the ran hot and the radiator was cracked. I replaced the radiator and the thermostat and it ran until it got hot then gauge went down and heat worked. Today he drove it and had no heat and idled up and down, I took the thermostat out and put in hot water and it works fine. Put thermostat back in and idled up and down again, drove car around and gauge went to hot and backed off but still no heat. Not sure if the heater core is bad or what but guess best thing is to take to mechanic and have looked at, right?

  • Anonymous Mar 06, 2009

    Same problem here....everything looks fixed but the problem comes back!!!! Alot of money later, still back at square one!



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Sometimes when a radiator goes bad its due to blockage in the radiator core. It takes an infrared temperature gage to be able to see hot and cold spots in the radiator core. Hot spots are where the blockage is, Cold spots are where the coolant is flowing through properly. When you drive down the road and your engine RPM goes up, your water pump spins faster creating more pressure forcing coolant through the blockage in the radiator, when you slow down the coolant flow slows down which causes the coolant to be trapped in the engine longer which in turn causes the coolant to heat up forcing the engine temperature gage to go up. Replace the radiator and use a 50/50 mixture of coolant and water. Once you've filled up the radiator with your coolant mixture, remove the Top radiator hose where it attaches at the T-stat housing at the engine to bleed the cooling system of any trapped air, Top off radiator and install the radiator cap. Then fill the coolant overflow reservoir to the cold level mark. Start the vehicle and turn the heater on to full hot, with defrost on and fan speed on maximum, with the engine running accelerate to about 2000 RPMs till you feel hot air at the windshield vent. Leave the vehicle running and visually check for any leaks and make sure to top off coolant level at the reservoir. Test drive vehicle leaving defrost on maximum speed to see if heat fluctuates. If heat fluctuation is present let vehicle cool down and repeat coolant bleeding step. If fluctuation is persistent another problem is present and it could be in the heater core. Use a coolant pressure tester to find any leaks in cooling system.

Posted on Mar 14, 2009

  • billzuhbub Mar 14, 2009

    If you had a blown head gasket you would see a brownish foam sludge on the engine oil dipstick or if you remove the radiator cap when the engine is cold you will see a grayish sludge on the bottom of the radiator cap. Also if you drain the engine oil you will see a brownish foam which looks like a chocolate malt. If you have crack in the cyclinder head most likely if you remove all the spark plugs you will see in one or more cylinders carbon build up where the sparkplug seats in the cylinder head.


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Solve? Although I clicked the link to solve the problem, I have no answers but am tempted to go after honda.

Same problems still occuring on my 2003 honda civic (103,000)!

I have:

-Changed thermostat's twice (180 degree; Yes, it is correctly positoned with the jiggle tab to the top and the correct side facing the engine)
-Installed new water pump
-Checked coolant level
-Changed the timing belt
-Checked for head gasket symptoms (white exhaust, corrosion in cylinders/plugs, loss of fluid, checked cylinder compression (all check out)
-Had the entire system presure tested 3 times with no visible leaks
-Run the car for 45 minutes with no visible drips/leaks
-proped the front of the car up to get air out of the system

This weekend I had spare time on my hands so I replaced the thermostat (checked the other, which according to bioling water at 180 worked as designed) I flushed the entire system, took out the radiator and had it blown out, flushed the entire system, installed new upper and lower hoses, checked the fan switch, I will be replacing the coolant with new, installing a new radiator (since they cost only 100 online and I have the hole front end off anyway, I'll be reinstalling the fans and switches, and trying it out again.

I drive about 100-450 miles between overheating, but it is very sporadic.

Still have the same heater issues- cold air when stopped and not accelerating at times. I am tempted to check the heater core next- but there is no loss of fluid from that ethier?

When I get the system back together, I'll try running the car for a few weeks without the heat on to see if that corrects the problem.

All of the steps to repairing the cooling system seem easy and cost 1/10 of getting them checked at a shop if you have the time!

I'll update again next week!

Posted on Jan 05, 2009

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I tired the coolant temp sensor and it didn't work also replaced the thermostat didn't work either

Posted on Oct 13, 2008

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Posted on Jun 12, 2008

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