boiling coolant and temp gauge fluctuating - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

aziankingz · 06-07-2009, 07:25 PM

I recently put in a new aluminum radiator (JVT racing 3 rows radiator) plus taurus fan. I bled it and it seems to not overheat, as per the stock temp gauge. While driving onto the highway the stock temp gauge suddenly drops to the first line and at a constant speed would be between the first and second line of the gauge. When on local roads it would go up to between the 3rd and 4th line, which I would say is normal, but when at a stop, the revs would kind of float at around 1500rpms and at times the idle would rise. I looked at the temp gauge and noticed that if i rev the needle would bounce from the 4th line then to the 2nd line then to 1st line then back up to the 4th line. Then I smelled coolant from time to time and when I finished driving to my destination (total of 20 mins on highway and 5 mins of local driving), i can hear coolant boiling in the reservoir, but the temp gauge shows no overheating. Any idea what is causing this issue?

06-07-2009, 07:25 PM	#1
aziankingz Nissanaholic! Join Date: Oct 2007 Location: NYC Age: 41 Posts: 1,735 Trader Rating: (28) Feedback Score: 28 reviews	boiling coolant and temp gauge fluctuating I recently put in a new aluminum radiator (JVT racing 3 rows radiator) plus taurus fan. I bled it and it seems to not overheat, as per the stock temp gauge. While driving onto the highway the stock temp gauge suddenly drops to the first line and at a constant speed would be between the first and second line of the gauge. When on local roads it would go up to between the 3rd and 4th line, which I would say is normal, but when at a stop, the revs would kind of float at around 1500rpms and at times the idle would rise. I looked at the temp gauge and noticed that if i rev the needle would bounce from the 4th line then to the 2nd line then to 1st line then back up to the 4th line. Then I smelled coolant from time to time and when I finished driving to my destination (total of 20 mins on highway and 5 mins of local driving), i can hear coolant boiling in the reservoir, but the temp gauge shows no overheating. Any idea what is causing this issue?