1997 Accord Temp Gauge Problems

[quote:2188cdedb8="ldevasier"]1997 Honda Accord, 4 cyl. LX, 4 door, automatic, 230K miles. When I start the car, temp gauge on dash goes to 40-50% range almost immediately. Temp continues to rise until it gets to 95% - 100% in red. I have replaced the temperature sending unit and the coolant switch (the bronze plug sensors that screw in around the water neck. I replaced the thermostat about 6 months ago. All fans work. When I get out and check under the hood, the car (hoses, radiator) are not real hot, seem normal. When temp gauge gets in red zone, it affects the temp output of the a/c (it gets much warmer). It will go down slightly if I turn off the A/C, but only about 5%.[/quote:2188cdedb8]

When you changed the Stat did you flush the cooling system, if so could be air lock. Try my remedy below.

Always bleed air from cooling system after replacing coolant. Set heater for maximum heat. Remove radiator cap. Loosen drain plug and remove drain bolt (if equipped) from engine block. Drain coolant reservoir. Fill coolant reservoir to MAX mark with 50/50 water-coolant mixture. Loosen bleed bolt and fill radiator up to base of filler neck. Close bleed bolt when coolant flows out without bubbles. Tighten bleed bolt. With radiator cap removed, start and operate engine to normal operating temperature. Add coolant if necessary and check for leaks.