Car overheating causes: low coolant, failed thermostat, water pump, head gasket, radiator blockage. Diagnosis and repair at Tedious Auto Repair Chico CA.
Most common cause. Coolant loss from a leak — radiator, hose, water pump, head gasket — leaves the engine without enough fluid to absorb and transfer heat. Check coolant level cold at the reservoir. If low, find the source before adding more.
The thermostat regulates coolant flow. A stuck-closed thermostat prevents coolant from reaching the radiator — the engine overheats rapidly even with full coolant. A stuck-open thermostat causes slow warm-up but rarely overheating. Thermostat replacement from $365.22.
The water pump circulates coolant through the engine and radiator. A failed pump (worn impeller, leaking seal, bearing failure) stops circulation. Overheat can be sudden. Water pump from $516.27 installed.
A blown head gasket allows combustion gases into the cooling system, pressurizing it and causing coolant loss and overheating. White exhaust smoke and coolant loss without visible external leak are key signs. Head gasket repair from $2,500.
A clogged or damaged radiator cannot dissipate heat efficiently. Bugs, debris, and scale buildup all reduce radiator efficiency. Radiator replacement from $573.18.
At low speeds and idle, the radiator fan pulls air through the radiator. Electric fan motor or fan clutch failure causes overheating in traffic while the car runs fine at highway speed. Fan motor from $250.
A deteriorated lower radiator hose can collapse under suction during cold starts, restricting coolant flow. Inspect hoses for softness, cracking, and swelling. Hose replacement from $120.
After cooling system work, trapped air prevents proper circulation. Proper bleeding procedure removes air. Overheating shortly after recent coolant work suggests an air pocket.
Buddy Rausch founded Tedious Auto Repair in Chico, CA in 2007. ASE-Certified. 18+ years serving Butte County. About Buddy Rausch