Car overheating; Hoses, thermostat, fan relay switch/heat sensor, and radiator all new?

Yes car is overheating. 1998 honda civic ex 1.6L vtec auto trans 178,000 miles My car is over heating and pushing coolant into the reservoir. This happens because I think maybe that the fan switch/relay and or thermostat heat sensor might be acting up. The fan turns on for 15seconds and then turns off. It seems... show more Yes car is overheating. 1998 honda civic ex 1.6L vtec auto trans 178,000 miles

My car is over heating and pushing coolant into the reservoir. This happens because I think maybe that the fan switch/relay and or thermostat heat sensor might be acting up. The fan turns on for 15seconds and then turns off. It seems to have a mind of its own. I feel like there is a leak in the system because that has always been the problem, a leak in the system. Either a hose or a thermostat patch or kinked coolant hose. There is a 170 degree duralast thermostat in there, new hoses, clamps, radiator, flushed coolant system, new thermostat heat sensor/relay switch fuse, and radiator cap is working good I suppose (1 to 1 ratio cap), and 50/50 coolant. There is no coolant leak visable anywhere. I do not see any oil in the coolant. There is the occasional pin drop of an oil looking remnant inside of the radiator when I take the cap off. I think that is just a coolant hose deteriorating, nothing that serious. So either I'm gunning it too hard and coolant is going into the reservior unnaturally, because this never used to happen, or there is another leak somewhere, or I need to lengthen the 15 second fan timer some how. Please if you know how to do THAT, please tell me how. Thanks.

Please, this problem has been an issue for 3 years. It has always been something different parts wise, but it has 100% of the time been an air leak, or pressure escaping issue.

Things that are out of the question as being the answer;
1. A malfunctioning water pump.
2. Low or old and unchanged oil.
3. Coolant mixture.
4. The fan relay switch/heat sensor or fan malfunctioning.
5. A toothfairy taking a blow torch to my engine while I'm driving.

Thank you
Update: To all it may concern: I found out that there is another sensor below the distributor, that senses heat. I found a post online that sounds as if I posted it. They baby their car, and the fix always seems to be so simple because it always has been simple. These people replaced this one sensor, and now their car... show more To all it may concern:

I found out that there is another sensor below the distributor, that senses heat.

I found a post online that sounds as if I posted it. They baby their car, and the fix always seems to be so simple because it always has been simple.

These people replaced this one sensor, and now their car is fine.

They did not however state what this sensor is, and there are 2 sensors sticking out of the engine under the distributor, not 1, 2 of them. They are also both COVERED in OIL.

Refilling/pushing the air pocket out after a nice long 100 mile delivery drive seems to cure the problem, but ain't enough.
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