Question - Just curious but why higher temperature on pre-facelifts? Is there a correct running temperature?
Answer - Facelifts and prefacelifts actually run at the same temp (if you check with specialist equipment). The markings on the gauge are in no way even close to accurate, particularly on the prefacelift - they are purely a guide.
Prefacelift Running TemperatureFacelift running temperatureThe gauge is heavily biased to keep the needle around midpoint on the gauge - for example, on a prefacelift, that bit between 92C and 98C actually covers from around 85C to 110C in reality, as is subject to a 12s delayed average, so as to keep the needle stable, even if the true temp peaks and troughs...
Bear in mind that the engine temp is also proportional to the ambient air temp in that, if its cold outside, its probable the temp on the guage will be a wee bit lower. Likewise, if its a blistering hot summer, the engine temp will rise a bit as the fans work hard to pass air through the rads. Temp may also be affected with aircon on as the condensor radiator will dispate a shedload of heat - straight into the path of the main rad!!
All said and done, if the needle barely rises off the bottom of the guage then its possible that the thermostat is stuck open allowing too much coolant through the radiators.
If the temp guage needle sits at half guage or slightly less, then that is more or less 'normal'.
If it climbs a tad above normal and is then brought back down by the fans cutting in then, again, that is normal.
If the temp rises a little when you use the 'eco' button that is also normal. When you are using the aircon (eco off) then the aircon condenser (or radiator as its normally known) is getting coolant cooled by normal airflow, thus keeping it cooled further than 'normal'.....
If the temp continues to rise then the fans will cut from low speed to full speed to enhance airflow through the rads in an attempt to bring the temperature down. In cases of emergency (motorway with no stopping places etc) then if the heaters are placed on high and the windows opened then you are further attempting to cool the system.
If it gets so hot that the red overtemp light illuminates then stop at the earliest safest opportunity and check the contents of the header tank. Remember DO NOT remove the header tank cap when its hot and pressurised. You WILL get hurt....