Only when the weather outside is hot like 95degees+ , the temp gauge goes up which looks like it overheating, and pop my hood and the coolant is boiling in the overflow bottle. This only happens when it is super hot outside, if it around 80degrees or less, it works perfectly fine, temp gauge stays the same. Coolant is normal color, not brown or anything different. Any ideas?

 

my guess is you have an un even mix of water and coolant?.... or your thermostat isnt opening all the way? hopefully more will chime in

 

Replace the thermostat and bleed the cooling system. Then go from there.

 

I know my mixture is pretty right of 50/50 water and coolant mixture. I dont think my thermostat is going crazy since it fine on cooler days and runs up to H on hotter days, but maybe I could try to replace it. Could it be my radiator fan as well?

 

Just get your car up to operating temp and see if your fan cuts on. My bet is going to be as stated, the thermostat isn't opening all the way. Another question (not sure it matters), did you mix the coolant and water or just poor in X amount of coolant then X amount of water to follow?

 

Does it happen when then vehicle is constantly moving or in traffic (stop and go)?

 

replace your thermostat and if your doing that bleed the coolant system also. and def check the fan. and 50/50 mix is the easiest way to go on coolant

 

When I drove slow like below 35mph, it gets hotter and temp gauge goes up. If I keep a constant ~40mph does goes down to normal level. I haven't test this on a full traffic of stop and go, just a light traffic where you can still cruise.

 

I had the same problem with my EK. I tried everything from a bleed, to a flush to a new tstat. My fan kicked on fine and it only happened when I was going 35mph or under. Do you have a stock radiator? If so, it is tiny and it can only handle so much abuse in the heat. I swapped in a bigger radiator (about $200) and I have not had a problem since... super simple process that will save you a lot of headache in the summer months. Also, water exchanges heat better than coolant and I know a bunch of guys that run 100% water in the summer (maybe with some water wetter). But don't forget to switch back to 50/50 during the winter if you are anywhere that gets cold.

 

Have you seen or heard your rad fan kick on? You test the system by disconnecting the rad fan switch located on the thermostat housing and jumping the 2 terminals on the disconnect side with the key on II fan should turn on. If it doesnt either the fan motor or relay is bad or wiring is messed up somewhere. If it does turn on start by bleeding the system correctly if problem persists replace the rad fan switsh.

 

I dont know if it my fan or not. I did notice my fan did not kicked on, so I wiggle the wires again, and it went back on. I drove it around for a while, the engine temp gauge did go up a little than normal, but slowly went back down. I noticed when I was parked, it went up then the light was green and gave it gas, it went back down to normal. My radiator is OE replacement after I had accident 8 yrs ago which the shop did the job.

 

what wires did you wiggle? where?