Okay I really need some help figuring this out because I depend on my car to get to and back from school. So let me get down to what has been going on.

My car is a 2000 civic dx sedan (edit: Automatic)

Okay so my car is ober heating while im at a long traffic stop or in very slow traffic but is normal at highway speeds.. This problem happened two weeks ago and thought it might have been the thermostat so I changed it and the problem went away, but now its back. I went to get a pressure tester to see if the radiator might not be working but my step dad said there was nothing wrong. He said that the head gaskets are the problem. But he told me to go and try and drive the car to school and check the coolant reservoir when I get back home to see if it changed level. It was not and I told him and he was confused. He told me to just keeo checking the reservoir and oil level and see if theres a change. The oil was changed today also.

Also does the radiator fan turn on when the temp guage hits halfway? Because it does turn on when it begins to overheat but not when it is halfway.
Thank you guys!

 

At what engine temperature does the radiator fan turn on? (I think you can use the diagnostic port to get an exact engine temperature)

What are you seeing that indicates to you the engine is overheating? Are you boiling over, or is your gauge just reading high?

 

Before a trip, when the engine is completely cold, check in the radiator not just the reservoir. The radiator needs to stay full to the top. Do not open the radiator except when completely cold.

Unplug the fan switch (on the thermostat housing) and jump the plug, which should make the fan run all the time the key is on. If fan does not run with switch jumped, troubleshoot the fan system.

Test drive with fan running all the time. If it does not overheat, replace the fan switch.

 

edit: actually, read my progress build in my signature--- I explained everything there, too from all the problems I had! -read this first though-

I had a major problem with this in my civic, before I swapped into a b20v from a d16y7 auto-

I literally replaced everything I could think of.

fan switch, thermostat, coolant temp sensor, radiator, etc.

mine did the same. ran fine on highway, but heated up past the middle of the heat gauge when slowed down / in traffic.
well.... I didn't want to believe it was the HG, because I wasn't seeing white smoke, or oil under the cap-

so I did a combustion leak detector test (rented it from autozone). basically, you pop the radiator cap, and put a plunger over the cap, and fill it with the blue liquid they make you buy. then you squeeze the turkey baster thing and after a few minutes of doing that with the car on, you see a change of the blue go to a yellow color, indicating that you have combustion gasses passing through your coolant system, basically saying your headgasket is busted through the water jacket.

combustion in your coolant means its not gonna cool properly, and itll end up blowing exhaust through your overflow coolant tank.
took me a long time to figure out what the hell was going on, so I pulled the headgasket in my driveway.

honestly, if youre gonna do it, leave the intake on the car as it makes the process much less time consuming.

happy trails and good luck. honestly, i'd just replace it, as I'm sure its due for a new timing belt, water pump and gasket.... also, NEW HEADBOLTS / ARP HEADSTUDS. be SURE to spray the headgasket with copper gasket maker, and be sure to torque the bolts in the correct sequence in torque increments...... 20 pounds for the first cycle, 40 the the next, 60, 75, then to spec (TWICE) - do NOT skip this part or youre gonna blow it again. also, take the time to do your valve lash/adjustment, since the motor will be cold, and freshly assembled and already top dead center. this will get you better power, mileage and less noise. lastly, don't over tighten your timing belt, or it'll whine and rob your power.

Good luck!
-Hatch Man

 

So are you saying the head gaskets it the problem? I am currently having this problem with my 98 honda civic dx. On the highways, the temp gauge is fine but as soon as i come to an idle my temp gauge starts to rise. Also I keep filling my radiator with antifreeze, and my overflow/reserve is becoming full to the top. So i need to keep emptying my antifreeze reservoir back down to the "full" line. It's like the system is not siphoning the antifreeze back into the radiator for some reason. So could this be my t-stat or fan not working properly? Or do i definitely need to change the head gasket?

 

Sound like a water pump problem.

 

Okay cool thanks for all the suggestions I'll try to do what all of you have said. I'll try to figure out the relay and use that combustion leak detector test to see what is up. If nothing is wrong then could it be the water pump then? I already had the timing belt and water pump changed about 20,000 miles ago. If it is the HG most likely what could happen is that my dad and I are gonna try and replace the gaskets ourselves. Hatch Man for telling me about your experience! I'll also get the head bolts too but did you mean that the head bolts and arp head studs are the same or I need both of them?

 

I went to check the radiator and it was low. I had to fill it up with a little less than a quarter of water. I think i will change the coolant just for safety?? I know it wont make that much of a difference but itll be better han using water for now right?

 

Hey again!
Hey I just noticed you said you have to keep filling the radiator back up. I also wanted to let you know mine did that too. I had to fill it up every two days or so, till it got so bad that it was pumping out exhaust fumes through the overflow reservoir which made my coolant simmer/boil.
Since you just changed out your pump and belt, I'd leave those be, hut the headgasket is Definitely the culprit, which will actually save you a good chunk of time. Few hours and you'll be set. Since you're still unsure of things, I'd ziplock bag your bolts and label them where they came off. You're gonna want to get new head bolts from honda, or buy ARP head studs. It's gonna cost about a hundred, but you need them, since they stretch when you torque them down, and they won't torque back to the specs they originally have, most time. I usually buy my parts from majestic Honda parts catalogue (online) because they're cheap, ship fast and it's always OEM and they have great diagrams.
Again, do your valve adjustment since the motor will be cold and top dead center before the head comes off too. Fairly straightforward. Every thing can be found on YouTube, no problem.
The difference between head bolts and head studs is....
One goes through the head like a regular long bolt, and head studs is headless bolt, you install into the block, slide the head over them, and put the nut head on then clamp the two. Saves time, and a good investment. For around the same price, too. Your call.

Other than that, you've just gotta dig right in and just do it.
Also, get some brake cleaner, an old toothbrush, and a plastic razor/drywall scraper, so you can clean your mating surfaces, and piston tops really well. Don't scratch the aluminum.

When you get the car to top dead center and put the belts back on, be sure to turn the engine a few times and make sure it's still in time also.