Coolant bubbling in the overflow bottle?

that exact same thing happened my vento was thermostat alright just hope thats all that wrong with yours

straight coolent, did ya bleed the system?
when i had overheatin and bubblin water it was a blocked rad.

straight (consintrate) coolant will cause an engine to overheat. concintrate coolant should be mixed 50/50... your problem sounds like thermostat or water pump to me..

take out that nismo stat and fire it away put back in the stock nissan one! and you will have no problems them nismo yoke are a disaster! iv had a few cars giving trouble with them yokes! and what pressure is the rad cap??