Car Overheating — Stop, Diagnose, Don't Push It

What's happening

The cooling system pulls heat out of the engine and dumps it through the radiator. Overheating means heat is coming in faster than the system removes it. Common chain: low coolant → trapped air → no flow → temps spike. Or: stuck thermostat → coolant doesn't circulate to the radiator. Or: failed water pump → coolant doesn't move at all.

You might also notice

• Temperature gauge above normal
• Sweet smell from the engine bay
• Steam from under the hood
• Heater stops blowing hot air
• AC stops cooling at idle

Likely causes (most common first)

1. Low coolant (look for leaks, white residue, or a wet driveway)
2. Failed thermostat (stuck closed)
3. Failed water pump
4. Cooling fan not running (P0480 or relay/fuse)
5. Clogged radiator
6. Blown head gasket
7. Air pocket trapped in the system after a recent fluid change

What to check first

1. Pull over, turn the engine off, let it cool 30+ minutes before opening anything
2. Check coolant level when cold (never open the cap on a hot engine)
3. Look under the car for puddles (orange/green/pink liquid)
4. With engine running, fans should kick on within ~10°F of redline — if not, suspect the fan circuit

Common OBD2 codes for this symptom

Don't have the code yet? Look up your code or read it with AXLY.pro.

Can I keep driving?

No. Continued driving while overheated warps cylinder heads and blows gaskets within minutes. Tow it.

Confirm with the actual code

Symptom-based diagnosis narrows the field — reading the actual stored code finishes the job. AXLY.pro is a free iPhone app that pairs with any Bluetooth OBD2 adapter and reads every stored DTC.