S14 overheating, thermostat gave up the ghost maybe?

[jdm_hero]

I could sometimes drive it just fine for any given amount of time and some other times the temp gauge in the cab will jet up real fast past hot and I kill the motor for a literally half a minute to a minute and the temp needle falls back slowly (10-15sec.) to normal. I sometimes hear a gurgling noise for a few seconds then it quits. I can tun the heater on full blast and it doesn't barely get warm at all. My ka24de has 171k on it so maybe something is turning south. Anyone have any idea what might be wrong, I did some searching and maybe a t-stat is in order, the seepage deal on the pump doesn't seem to be leaking so I hope it's working fine. Radiator is plenty full of coolant. Thanks

Also when I go to replace the t-stat what brand should I get (autozone,ect?)

[Space Monkey]

unless you getting a nismo thermostat there is no difference between other ones besides the price. Its just a cylinder full of wax and a small piston. unless you are boosted just get a normal t-stat.

[jdm_hero]

I took it for a good spin, didn't overheat but I have the same issue most everyone else had when I searched "overheating", hot pressurized upper hose and cold lower hose. Is this a good sign of a blocked radiator or sign that the water pump isn't pushing?

[devil_child]

you may have air in the system not allowing it to get hot enought open the tstat. For it to get hot enough, you need pressure. To get higher pressure, you need a completely bled system. Try jacking up the front end and following FSM procedures to bleed it. Go from there.

If it is still overheating, you have a bad tstat. go to a local autostore buy it and the water outlet gasket. replace them, bleed system etc etc.

[jdm_hero]

I replaced the t-stat today and started doing a coolant flush, I ran out of day light so I'll finish tomorrow but I did notice that the tstat opened up quicker and made the heater in the cab work great! Hopefully this fixed my problem. I will report back asap. Thanks guys

[jdm_hero]

So I changed my thermostat, done a coolant flush a few times, checked to see if the water pump works, and bled the system with the front of the car jacked up like 2ft. I'm assuming there's air in the system still despite bleeding thorough for about an hour. I drove down the road about 5min and the temp gauge went up to hot, I stopped and let it chill for about 30-45 seconds till the gauge dropped back to normal. I then drove like 20 miles worth of hwy/city driving and only had it barely raise right up to the H mark then drop real fast. There after about 40 minutes i was doing residential area driving and it shot back past hot. I turned it off and heard the nastiest boiling gurgle sound ever. After a minute or so it went back down, i'm confused