After driving in the freeway for 40 miles, the temp gauge start to go overheat and goes down after a couple of second, then start repeat same process. I notice that there's too much pressure on the upper and lower radiator hose. coolant at the reservoir fills up but never goes back to the radiator.

test and changes I have done:

1. replaced the radiator, properly burp it to makes sure there's no air. still having the same problem, so I bought a new radiator cap, same problem.

2. replaced the coolant reservoir tank, same problem

3. checked for blown head gasket using the tester from autozone, negative result

4. checked the radiator fan fuses and relay, everything is good

5. replaced the coolant temp sensor, same problem

6. test the thermostat by putting is on a boiling water, it opens up. drill 2 tiny hole on the thermostat to take out trap air

Didn't replaced the radiator fan switch because the radiator fan turns on if its overheating.

I'm pretty much about to give up, I don't know what to do next. Any suggestions will be high appreciated. THANKS

 

The fan isnt' suppose to kick on if its overheating, it kicks on when the fan switch reaches a certain temp.

Bleed your coolant again, but this time raise your front end a bit, keep the heater on and closely monitor the coolant from the opening of the radiator. If it keeps bubbling you probably have a leaking headgasket. Which will lead you to test the coolant for combustion.

 

Why drill holes in the t-stat? If you purchased the correct part, there should be a jiggle pin that allows air to pass through. @ what temperature did the thermostat open? should be ~180 degrees.

 

You should put in a new thermostat first and then re bleed the system with the heater on. Technically the system is self bleeding when the radiator neck is the tallest point in the cooling system (when you're parked on a hill). It sounds like you still have an air bubble in your Heater hoses

 

I bleed the coolant that way, no bubbling of coolant

 

The one I got a jiggle pin, I took off the pin and drill another small hole, they said it helps take air out. I'll test the thermostat again and check what temp it opens up. thanks

 

I'll test the thermostat again if its bad, I'll replaced it and re bleed it again. thanks

 

Honda engineers designed the thermostat with one jiggle pin for a reason.
Replace your butchered thermostat with an OEM part.

Sounds like you have one of these two problems:
1. Incorrect thermostat. Thermostat is not opening at the correct temperature.
2. Air in your coolant. Common symptom is coolant boiling over into overflow container.

Side note: To test a thermostat, you should heat water up to ~180 degrees. Place a cooking thermometer in the water, then submerge the thermostat in the hot water. At ~180 degrees, the thermostat should begin opening. Use the cooking thermometer to verify that the thermostat is opening at the correct temperature.