Car overheating? What to do right now, and why it happens

What to do right away

• Turn off the A/C and turn the heater to maximum heat with the fan on high.
• If you are stuck in traffic, keep a gap and avoid revving the engine.
• If the gauge keeps climbing, a warning light comes on, or you see steam, pull over somewhere safe and turn the engine off.
• Turn on your hazard lights and stay away from traffic.

What not to do

• Don’t open the radiator cap or the coolant reservoir cap while the engine is hot. The coolant is under pressure and can cause serious burns. Wait until the engine has fully cooled, which takes a while.
• Don’t pour cold water on a hot engine.
• Don’t keep driving "just a few more blocks" with the gauge in the red. That is how head gaskets and engines get damaged.

Common causes

• Low coolant, usually from a leak in a hose, the radiator or the water pump.
• A radiator cooling fan that doesn’t turn on.
• A thermostat stuck closed.
• A failing water pump.
• A clogged or damaged radiator.
• A failing head gasket, which can also cause white exhaust smoke or coolant loss with no visible leak.

Why it happens in traffic and not on the highway

At highway speed, air flows through the radiator on its own. In stop-and-go traffic the car depends on its electric cooling fan. If the gauge climbs while you are stuck in traffic but drops once you are moving, a fan problem is a likely suspect.

Signs to watch for before it overheats

• The temperature gauge sits higher than usual.
• A sweet smell, or puddles of green, orange or pink fluid under the car.
• You keep having to top up coolant.
• The heater blows cold air when the engine is warm.

How we handle it here

• We pressure-test the cooling system to find leaks, and check the fan, thermostat, water pump and radiator.
• We explain what failed and give you the price before any work starts. Nothing is done without your approval.
• We are open 24/7. If the car is overheating, call us before driving it further.
• We speak English and Spanish.