my honda accord (96) overheats SOMETIMES, and only at a standstill. on the freeway it is fine. I have changed the thermostat, the radiator cap the switch and bled the system. I have had the head chk and there isn't any visible leaks and the antifreeze needs to be added may be every 2 days some times the reservoir for the antifreeze gets full only SOMETIMES there is a smell that comes through the car when i accelerate. even on the freeway it smells bad. Could a loose cover on my catalytic converter be causing the overheat. any ideas will be appreciated.
You should sort out all problems you have with your car:
- Antifreeze leaking. Do a pressure test for the cooling system, or find some other way to find where it's leaking. It may be leaking internally to the cylinders or externally. Please check oil for presence of antifreeze and antifreeze for presence of oil.
- Overheating. This may be a faulty sensor (the sensor that controls the fan may be different from the sensor that show the temperature on the dashboard). It may also be a faulty fan or a faulty wiring to the fan, or a failed fuse, etc. If you know which pin gets the positive voltage and which gets the negative voltage, you can test the fan by connecting it directly to the battery.
I'm not yet convinced that your problems are connected. Overheating may be caused by a faulty fan or fan control especially considering it overheats only at standstill. Antifreeze disappearing is due to an internal or external leak.
I don't believe catalytic converter cover would cause overheating of the engine. A faulty catalytic converter or catalytic converter connected to faulty engine that doesn't burn all fuel could overheat itself, but I have never heard the cat causing overheating of the engine. Perhaps a clogged cat could lead to engine trouble, but a catalytic converter cover? No.