The cooling fan does the work in traffic
At freeway speed, air is forced through the radiator by the vehicle's own movement. The faster it goes, the more air passes through, and the cooling system has an easy time of it.
In stop-and-go traffic that airflow disappears. A vehicle crawling along a jammed road, or waiting in a drive-through line, is relying almost entirely on the cooling fan to pull air through the radiator. If the fan is not working properly, the engine can be perfectly happy on the open road and overheat within minutes in a queue.
That pattern is the giveaway. A temperature gauge that stays normal at speed and climbs when the vehicle is barely moving points at the fan, its relay, its wiring or its controls, long before it points at the radiator or the water pump.
A check you can do yourself
With the engine warmed up and the vehicle parked safely, turn the air conditioning on. On many vehicles that brings the cooling fan on, and you should hear it running at the front of the engine bay. If it stays silent, mention that when you book.
Keep hands, loose clothing and tools away from the fan. It can start on its own at any time while the engine is warm, and on some vehicles even after the engine is off.
Other signs worth booking for
- Coolant that needs topping up more than occasionally.
- A sweet smell or drips under the front of the vehicle.
- Steam from under the hood, which means stop and switch off.
- Weak heat from the heater on a cool morning.
The national cooling system page covers what to do if the gauge goes into the red. A fault traced to the engine itself is engine repair, and an A/C system that stops cooling while the engine runs hot may share a cause, so A/C service is worth mentioning at the same visit. This is the Commercial & Consumer listing; the Phoenix city page explains the others.
About this store
The Phoenix store runs eighteen services and is managed by Patrick Taylor.
See the national cooling system page for all 33 locations.