I have an issue with my nissan premera car.its tp11 2000 model with 1.8cc.the previous radiator started to coolant leak. So I replaced a recon radiator of fb15.but after few days ago I realised the car temperature goes up at the certain time . specialy wen I drive in up cuntry areas and the trafic time.but dis is not hapend always.next thing is the temperature goes up and within few second it goes down.i checked that then I got to know when both fans are on, the temperature goes down. I sent it to garage but he checks the temperature with gage and said nothin wrong with the temperature. But still meter indicates temperature goes up and with both fans on it goes down.pls help.
tnx.