The temperature gauge in my car goes up and down. It usually doesn't happen in the morning, but happens when I leave work at 1 p.m. It doesn't matter if the air conditioner is on or not, it still fluctuates. Could the hot weather be affecting it because of the age of my car (1998)? We replaced the thermostat and the radiator. There is a crack in the catalytic converter, I think that's what it is, but I don't know if that could have anything to do with the temperature. I'm also loosing coolant, we suspect there's a leak somewhere? We just can't find it. Knowing nothing about cars, im at a loss on what the temperature issue my be.
My car has a manual transmission.
The temperature of the cooling system can be read directly to determine if you are seeing an actual fluctuation in temperature versus perhaps just a malfunctioning gauge. A blocked exhaust would cause higher engine operating temperature but a crack in the catalytic converter would not affect temperature. If you have a break in the exhaust system though do address that promptly as otherwise you may be needlessly exposing yourself to carbon monoxide. With regard to the coolant leak, that leak can be identified and resolved in a cooling system leak diagnostic. I would suggest requesting the leak diagnostic and during that visit the possibility of overheating versus a gauge malfunction can be considered by the mechanic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing