If the temperature gauge climbs toward hot, pull over and shut the engine off, since driving on can warp the cylinder head. Leaking radiators, stuck thermostats, and failing water pumps are the usual causes. Cincinnati Auto Repair handles cooling system and radiator repair in Cincinnati; phone (513) 666-5717 and say where the coolant is going.
Steam from under the hood, a sweet smell, or a gauge past the middle mark all mean the same thing: stop, and do not try to reach home first.
The cooling system is a sealed, pressurized loop. A small leak turns into a big one under heat, and that is why a pull-over today is cheaper than a head gasket next week.
What should you do in the first few minutes of an overheat?
Switch on the hazards, get off the road, and turn the engine off. Do not open the radiator cap or the coolant reservoir while the engine is hot, because the system is under pressure and the coolant can spray out.
Check the coolant level only after the engine has cooled. If it is low and you add some, treat that as a stopgap. If it overheats again, have it towed.
Can a leaking radiator be repaired, or does it need replacing?
A leak at a hose connection or a drain plug is a small fix. Seam leaks where a plastic tank meets the aluminum core usually mean replacement, and a core clogged with deposits often does too.
Ask for a pressure test before anyone quotes a radiator. It shows whether the leak is the radiator at all, or a hose, the cap, or the water pump.
Where is the coolant going if there is no puddle?
A damp passenger-side carpet and a fogging windshield point to the heater core. White exhaust smoke or milky oil on the dipstick points to a head gasket, which is the repair you were trying to avoid.
Why does my car overheat only in slow traffic?
At speed, air pushes through the radiator. In traffic the cooling fan has to do that work, so a failing fan, low coolant, or a clogged radiator shows up first at a standstill.
Is it okay to top off coolant with plain water?
For a short trip to a shop, yes. Water dilutes the mix, so the system should be restored to the coolant type and ratio your owner's manual specifies.