It is not unusual with any 10-year old stock radiator for the temperature to rise during summer. If you have this, don't panic. The engine can run all day close to the "H" mark. Just don't let it go over that.
If this worries you, fit a slightly larger radiator, like the B210 radiator.
Accoring to Owner's Manual: Water Temperature Gauge, this is the normal range.
Normal Range
Use the stocko fan. Electric fans are notorious for failing to cool the radiator in stop/go traffic.
What is the correct temperature the engine should run at? Primarily, this depends on the thermostat. You can get different temp thermostats, and the coolant should stay steady at that temperature:
- 160F degree (71C)
- 180F degree (82C)
- 195F degree (91C)
- 212F degree (100C)
160-degree is good for drag racing, or for use with low octane fuel. 180 is recommended for all street cars, it will keep the oil at optimum temperature (oil runs about 20 degrees hotter than the coolant). 212 degree is only run on emission-control cars along with a 14 lb. radiator cap to prevent boiling.
After the thermostat, the radiator is the next factor. If your temp. stays steady except on the hottest summer days it seems you need a replacement radiator, either a new or rebuilt stock unit, or a larger used unit (from a B210 or B310).