04 honda overheating

i drive a 2004 honda civic. i recently drove from MA to LA. i had the car checked before my trip just to be safe, and it was also overheating and i knew it was the cooling fan. my mechanic fixed the fan as well as did an oil change and said the car is in good condition for an 04. However, about half way through my trip my car started overheating agin. it only does so when the car is on and standing still ( in traffic, parked ect.) no lights come on on my dash, and when i drive it, i turn the heat on at stoplights or in traffic & avoid driving it on the highway. any ideas on what it could be? coolant fan& oil change were about 2 weeks ago. i don’t have another info on when other things were replaced (head gaskets or coolant flush)
thank you

Your cooling fan does not work. That is causing the overheating. Check the fan relay, temp switch and the fan itself.

i just had the fans replaced a little over 2 weeks ago and they still work fine

You can see them work? You have verified they still work?

If they do work, I’d suggest a pressure test to make sure the head gasket isn’t failing. If your coolant level keeps dropping or if you see bubbles in the radiator with the cap off (take it off cold, then warm it up) then a bad head gasket is likely. I’d also suspect a bad water pump but they usually fail by leaking coolant. Thermostats usually fail open so the car won’t overheat but have been know to fail closed as well. Cheap to replace and eliminate as a problem.

This sounds like what happened to my '98 Civic when it needed a new head gasket.

If the fan was fixed, it may have been too late, and the head might have been warped enough that the head gasket leaks. It doesn’t take much heat to warp an aluminum head.

The only way to know for sure is to get the system pressure tested and the radiator flow tested. If it’s the original radiator, its passages might be clogged, and replacing the radiator would be in order.

The important thing is to get it tested so the problem can be properly diagnosed, not just throw parts at it.

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Fan would be the first place to look. Just because they were just fixed doesn’t mean they are currently working. And everything else @Mustangman said.

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yes, i just checked them again today and both still work fine
& ok thank you i will look at those

okay thank you, i just wanted to see if its something i could possibly do myself or if i had to take it in for tests.

If it is a fan issue, the car would not overheat on the highway since it has good airflow. So, now. You idle motor and open hood and see fans spinning but temp gauge is hot? Not normal, but HOT? Do the math. Fans work. Motor is overheating. Either radiator is plugged. Or head gasket is failed.


i checked them yesterday and they’re still working, coolant is fine. its an issue with the head gasket

A new radiator is cheaper than a head gasket. Though most cars for sale with bad headgaskets also have new radiator and water pump. Hmm. A good tech can can show you symptoms of bad headgaskets. You can say show me and I will pay you to fix it. So he might show you

Could be. Some Honda engines a few years ago developed cracks in the block - although maybe not in an area where it would let exhaust gasses into the cooling system. Anyone here know more about that? Not many Honda engines have fatal flaws but it can happen.

Definitely sounds like a radiator fan problem, but OP says they have visually verified the radiator fan is spinning like a banshee at the same time this overheating in low speed traffic is happening. If it was the head gasket you’d think it would overheat on the highway too. hmmmm … OP, any overheating on long-ish drives at 60+ mph?

I’m sort of leaning towards the cooling system isn’t maintaining its proper pressure, either b/c of a failed pressure regulating cap, or a cooling system leak. It doesn’t take much of a leak, could be a small leak that doesn’t produce much if any coolant dripping under the car. OP, do you need to add coolant once in a while? If so, how much per 1000 miles?

The cooling system will usually do the job easily when all these parts are working correctly, so it is almost certainly one or more of these. Sometimes you just have to go through each one, one by one.

  • thermostat
  • radiator
  • radiator cap
  • cooling system holds pressure
  • water pump
  • radiator
  • engine compartment fans and coolant temp sensor
  • engine timing and air/fuel ratio
  • head gasket

One idea, sometimes when there’s a head gasket leak you’ll be able to see small bubbles coming up through the coolant in the radiator when the engine is running. Good idea to ask your shop to check.

If you do not have other symptoms that indicate a head gasket issue and those symptoms are many…then I would change the thermostat first and foremost. You already verified that the fans are working when you are in traffic, so that is good. It is possible to have working fans and a clogged radiator and or a bad thermostat.

If you do not stop this overheating you WILL have a head gasket problem, so now is your chance to catch this issue while it is still easy to solve. Any competent mechanic should be able to fix this, the ones who cannot, shouldn’t be in the business.

I’d change the thermostat at this point in time and if that doesn’t fix it, it is the radiator… This of course assumes you do not have obvious head gasket symptoms.

** You also stated that you are avoiding highway driving…the highway is where your engine has the best chance to stay cool…it is stop and go traffic that is the hardest on the cooling system, just fyi.

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