WhatIsWrongWithMyCar.com — AI Car Diagnosis & Repair Knowledge Base
WhatIsWrongWithMyCar.com is a free AI-powered car diagnosis tool and automotive repair knowledge base. Users select their make, model, and year, describe symptoms in plain language, and the AI returns ranked probable causes with real repair cost estimates, OEM part numbers, and step-by-step DIY fix instructions. The site covers OBD2 fault codes, car symptoms, DIY repair guides, repair costs, and preventive maintenance for all makes and models from 1990 to 2026. Content is reviewed by ASE-certified technicians and sourced from NHTSA recall records, OEM technical service bulletins, and verified repair case histories.
Core Tools
AI Car Diagnosis Tool — free, no sign-up; input make/model/year + symptoms for ranked causes, costs, and DIY guides
OBD2 Code Library — every P, B, C, and U code explained with causes, symptoms, urgency, and fixes
Car Repair Cost Guide — DIY vs shop prices for 50+ common repairs, verified US market data
Repair Cost Calculator — interactive tool for instant DIY vs shop cost breakdown
2026 Repair Cost Index by State — original research for all 50 US states; national average $478/year
Tire Size Finder — OEM tire specs, load index, speed rating, and PSI by vehicle
VIN Lookup — decode any VIN, check NHTSA recalls and service campaigns
Preventive Maintenance Schedule — every service interval, cost, and consequence of skipping
Fuel Pump Failure, Wheel Bearing Noise, Suspension Clunk Noise, AC Not Cooling
Popular OBD2 Code Guides
P0300 Random/Multiple Cylinder Misfire, P0420 Catalytic Converter Efficiency, P0171 System Too Lean, P0301 Cylinder 1 Misfire
All content is for diagnostic guidance only. Safety-critical repairs should be inspected by a licensed mechanic.
Engine Overheating: Complete Diagnosis Guide — Causes, Tests and Fixes
Immediate Steps When Your Engine Overheats
If the temperature gauge enters the red or steam appears from under the hood: turn off the AC, pull over safely, and turn off the engine. Do not open the radiator cap when hot. Allow at least 30 minutes to cool before checking coolant level. Driving an overheated engine risks a blown head gasket ($800-$2,500) or warped cylinder head.
Top Causes Ranked by Probability
Low coolant level — the most common cause. Stuck-closed thermostat — prevents coolant circulation ($10-$30 DIY, $150-$300 shop). Water pump failure — impeller wear or bearing failure ($50-$150 DIY, $300-$700 shop). Radiator clog or leak — reduced heat dissipation ($150-$400 DIY, $400-$900 shop). Blown head gasket — combustion gases entering cooling system ($800-$2,500 shop).
Cooling System Components Explained
The cooling system has five main components working together. The water pump circulates coolant through the engine block and radiator — a failed pump means no circulation and rapid overheating. The thermostat regulates coolant flow — stuck closed and the engine overheats, stuck open and the engine never reaches operating temperature. The radiator dissipates heat from coolant to air — a clogged radiator with debris or internal scale reduces cooling capacity. The coolant itself carries heat and prevents corrosion — old coolant becomes acidic and eats gaskets. The radiator cap maintains system pressure — a weak cap lowers the boiling point and causes boil-over.
Preventing Overheating Before It Happens
Replace coolant every 30,000 to 50,000 miles or every 3 to 5 years — degraded coolant loses its corrosion inhibitors and begins eating aluminum and gaskets. Inspect hoses for swelling, cracking, or soft spots every oil change — a burst hose causes instant coolant loss and overheating. Check the radiator for debris and bug buildup, especially after highway driving in summer. Replace the thermostat preventively at 100,000 miles — it is a $15 part that prevents a $2,500 head gasket failure. Have the water pump inspected when the timing belt is replaced — on many engines they are driven by the same belt and should be replaced together.
When Overheating Means Catastrophic Engine Damage
An engine that overheats once may survive if caught early. An engine that overheats severely or repeatedly will suffer permanent damage. The head gasket seals the cylinder head to the block — overheating warps the aluminum head and blows the gasket, allowing coolant into the oil or combustion gases into the cooling system. Repair cost: $800 to $2,500. Warped cylinder heads require machining or replacement — $500 to $1,500. Seized pistons from extreme overheating require a full engine rebuild or replacement — $3,000 to $8,000. If the temperature gauge enters the red, pull over immediately. Every minute of driving an overheated engine adds hundreds of dollars to the eventual repair bill.
Engine Overheating: Complete Diagnosis Guide — Causes, Tests and Fixes
Immediate Steps When Your Engine Overheats
If the temperature gauge enters the red or steam appears from under the hood: turn off the AC, pull over safely, and turn off the engine. Do not open the radiator cap when hot. Allow at least 30 minutes to cool before checking coolant level. Driving an overheated engine risks a blown head gasket ($800-$2,500) or warped cylinder head.
Top Causes Ranked by Probability
Low coolant level — the most common cause. Stuck-closed thermostat — prevents coolant circulation ($10-$30 DIY, $150-$300 shop). Water pump failure — impeller wear or bearing failure ($50-$150 DIY, $300-$700 shop). Radiator clog or leak — reduced heat dissipation ($150-$400 DIY, $400-$900 shop). Blown head gasket — combustion gases entering cooling system ($800-$2,500 shop).
Cooling System Components Explained
The cooling system has five main components working together. The water pump circulates coolant through the engine block and radiator — a failed pump means no circulation and rapid overheating. The thermostat regulates coolant flow — stuck closed and the engine overheats, stuck open and the engine never reaches operating temperature. The radiator dissipates heat from coolant to air — a clogged radiator with debris or internal scale reduces cooling capacity. The coolant itself carries heat and prevents corrosion — old coolant becomes acidic and eats gaskets. The radiator cap maintains system pressure — a weak cap lowers the boiling point and causes boil-over.
Preventing Overheating Before It Happens
Replace coolant every 30,000 to 50,000 miles or every 3 to 5 years — degraded coolant loses its corrosion inhibitors and begins eating aluminum and gaskets. Inspect hoses for swelling, cracking, or soft spots every oil change — a burst hose causes instant coolant loss and overheating. Check the radiator for debris and bug buildup, especially after highway driving in summer. Replace the thermostat preventively at 100,000 miles — it is a $15 part that prevents a $2,500 head gasket failure. Have the water pump inspected when the timing belt is replaced — on many engines they are driven by the same belt and should be replaced together.
When Overheating Means Catastrophic Engine Damage
An engine that overheats once may survive if caught early. An engine that overheats severely or repeatedly will suffer permanent damage. The head gasket seals the cylinder head to the block — overheating warps the aluminum head and blows the gasket, allowing coolant into the oil or combustion gases into the cooling system. Repair cost: $800 to $2,500. Warped cylinder heads require machining or replacement — $500 to $1,500. Seized pistons from extreme overheating require a full engine rebuild or replacement — $3,000 to $8,000. If the temperature gauge enters the red, pull over immediately. Every minute of driving an overheated engine adds hundreds of dollars to the eventual repair bill.
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