Hey guys, it's my first day registered on Honda-Tech and I just wanted to introduce myself as well as try and get some advice troubleshooting my Civic.

My name is Matt. From San Antonio TX.

I bought a car off a neighbor for $2000 for my girlfriend to get to and from work. I've been having quite a few problems and I'm looking for some advice on an issue I've been having with it overheating. First off I am not a mechanic and welcome any corrections on where to post this and appreciate any advice I get along the way.

1998 Civic EX
Coupe
Manual
D16Y8
SOHC
V-tec

So this car has been overheating and I have been swapping parts and trying to figure out why but haven't had any luck yet.
Here's what I've done:

New thermostat (x2)
New radiator
New rad cap
flushed and replaced coolant (multiple times)
burped cooling system (quite a few tiimes)
New water pump
New fan switch
found and sealed a leak from thermostat housing

No leaks from cooling system (that i can see)
Upper radiator hose heats up but the bottom one does not. Its almost like it doesn't circulate all the way around.
Idling, I let the motor heat up (Needle sits slightly under the center of gauge)
As it sits idle with neither fan running, it gets hotter and hotter.
With the rad fan on it still doesn't cool down
With the a/c button pressed and the fan speed on full, the temp does drop to normal almost instantly. Doesn't matter if it's on hot or cold dash setting.
It does the same while in motion

Disclaimer(The radiator fan has never really kicked on by itself, I've tested the fan, replaced switch, relay and fuse are good, so I've just shorted the plug at the switch to get it to turn on)

 

Hows your engine oil?sounds like your rad fan is weak.if it cools down while driving(due to wind/air) then hot when stop,then its the rad fan

 

Maybe the coolant temp sensor is bad? Have a you done a compression test? Does the heater work?

 

Oil is good, no milkiness or anything. It does cool slightly when I'm motion but not much. Only heater on max seems to get it to normal temp.

 

Coolant temp sensor would be on the block under distributor, correct? It did have some janky butt splice connecting it to the harness. Heater does work, almost too well... Would the heater core be to blame? Headed to my buddies shop to do a compression test and maybe combustion test on rad to rule out a head gasket leak.

 

"No leaks from cooling system (that i can see)
Upper radiator hose heats up but the bottom one does not. Its almost like it doesn't circulate all the way around."

Just from hearing this, it sounds like you need to use a Florescent dye in the coolant and a black light to see if you can pin point it on the radiator or just buy a new radiator. Or usually if the big radiator hose is hot and bottom is cold then the thermostat is closed untill the engine reaches a certain temperature. Also when you buy anything for the hot or cold aspect of a car please get a big cup, tie a wire string or cloth to it [the car part you bought] like sensor or thermostat and dip it in the cup [cup of very hot or boiling water] to see if it works do u understand this tip? Because I have bought a thermostat before when I was in my teens and I installed it only to find out it was doing the same thing and after removing the thermostat and many hours of troubleshooting I found out that new parts also sometimes don't work [can you believe that] wow! I mean like it's new so you should not have an issue but this for anything with hot and cold. Also if your wondering how to test the hot or cold sensor that go's to your radiator, unplug the wire from the radiator and plug the connector into the new one you just bought to test it with cup of hot/boiling water dip it in to see if new sensor is good or bad sometimes it could be the 5th or 3rd one you buy exchange till you get one that actually works.