If it is not overheating then the temp gage or the sending unit are bad.
Idle the engine, remove the temp sensor wire on the engine and ground it. If the gauge does not move one can assume it has failed.
Your 1994 Honda Civic will overheat when the thermostat is malfunctioning. The overheated engine can experience the idle to surge. The engine should be turned off immediately.
Low Coolant or faulty gauge
To adjust the idle on a 1994 Isuzu 2WD truck, locate the idle adjustment screw on the throttle body, usually near the throttle linkage. Start the engine and let it warm up to normal operating temperature. Use a screwdriver to turn the idle adjustment screw clockwise to raise the idle or counterclockwise to lower it, checking the RPM gauge as you adjust. Once the desired idle speed is achieved, make sure to recheck any other engine parameters for optimal performance.
Normal engine operating temperature is 190-215 degrees F.
In cold weather, you'll notice that the engine temperature gauge registers only slightly or not at all, particularly if you're driving at highway speeds. You'll also notice that the temperature of your passenger compartment heater isn't nearly as warm as usual. Your car will show a temperature if you allow it to idle for several minutes. The heat flowing into the passenger compartment will be warm as usual. If your thermostat is open, the engine will rarely warm to a level you're used to seeing on the temperature gauge.
To adjust the engine idle on a 1990 Mazda Miata with a 1.6 engine, locate the idle adjustment screw on the throttle body. Start the engine and allow it to reach normal operating temperature. Then, use a screwdriver to turn the idle adjustment screw clockwise to increase the idle speed or counterclockwise to decrease it, aiming for an idle speed of around 850 RPM. Always double-check the idle speed with a tachometer after making adjustments.
To set the engine idle for a 350 engine, first, ensure the engine is at normal operating temperature. Then, locate the idle adjustment screw on the carburetor or throttle body and turn it to increase or decrease the idle speed as needed. Typically, the idle speed should be between 600 and 800 RPM for a 350 engine, but consult the owner's manual for specific recommendations. Finally, recheck the idle speed after adjustments and make sure the engine runs smoothly without stalling.
To properly idle a Caterpillar 3406B engine, ensure that the engine is at operating temperature before transitioning to idle. Allow the engine to idle at a low RPM, typically around 600-800 RPM, to maintain optimal oil pressure and temperature. Regularly check for any unusual noises or vibrations during idling, and ensure that the engine has adequate fuel and cooling. Finally, avoid excessive idling to reduce fuel consumption and minimize wear on engine components.
My Altima had that problem and it was the water pump going out. It started with temperature gauge was moving, but then it started leaking and finally the heater stopped being warm at idle.
Yes, coolant temperature sensors can affect idle speed and cause the engine to run rough in a 1992 Cabriolet. If the sensor is faulty, it may send incorrect temperature readings to the engine control unit, leading to improper air-fuel mixtures. This can result in an unstable idle and rough engine performance, as the engine may not be receiving the correct adjustments for temperature changes. Therefore, ensuring the coolant temperature sensor is functioning correctly is important for optimal engine performance.
No............... Just let the engine get to its operating temperature and service it out at an idle only......