Why Does My Car Overheat in Long Island Traffic but Not on the Expressway?

Your radiator uses air moving through its fins to lower the temperature of your car’s coolant. At highway speeds, airflow is constant and strong. Even a weak cooling system will work efficiently when you’re moving at speed. In traffic, everything changes.

• Lower speeds mean less air naturally passes through the radiator.
• Your cooling fan turns on when there’s less air movement, but if there’s a problem with the fan or elsewhere in the system, it won’t do enough to cool your engine.
• Idling and frequent braking generate heat without airflow to dissipate it.

If you see your temperature gauge rising, it’s time to visit a Suffolk County auto repair shop for cooling system or radiator repair. 

If your car only overheats in slow traffic, the problem is likely related to one of the following:

• A failed cooling fan, malfunctioning fan relay, or failed fan control module.
• Low coolant levels  with reduced overall cooling capacity.
• A clogged, dirty, or damaged radiator  with restricted airflow. Clogged radiators are more common on Long Island after winter, due to high use of road salts.
• A failing water pump that struggles to circulate coolant.
• A stuck thermostat.

You can look for coolant spots underneath your car in areas where you park. If you see bright colored liquid, it’s likely that you have a coolant leak.