Your car starts and runs perfect for 20-30 minutes, then dies. Maybe restarts after sitting, maybe leaves you stranded. This is almost always a heat-related failure. Here is how to track it down.
Crank sensors are notorious for working cold and dying hot. Engine just dies, often will not restart for 30 minutes. P0335 code sometimes, sometimes not.
Get a full diagnosis →A weak fuel pump gets weaker as it heats. After 20-30 minutes of operation, internal resistance goes up and the pump cannot supply enough fuel. Common on older Hyundai, Ford, and GM.
Get a full diagnosis →Coils that work cold can fail at full operating temperature. Especially common on older Ford TFI ignition modules and GM HEI distributors.
Get a full diagnosis →A purge valve that opens too much when warm dumps excess vapor and stalls the engine. Will often restart in a minute. Codes P0441 or P0496.
Get a full diagnosis →Common on older GM, some Ford. Worn contacts inside the switch overheat and lose connection. Engine just dies, like the key was turned off.
Get a full diagnosis →A MAF that fails when hot causes the ECU to lose its main fuel signal. Engine stalls, often restarts after cooldown. Clean first, then replace.
Get a full diagnosis →| What You Notice | What It Usually Means |
|---|---|
| Dies after 20-30 minutes of driving | Heat-soak failure: crank sensor, fuel pump, coil |
| Restarts after 20-30 minute cool down | Heat-related, confirm with hot test |
| Loses power gradually before dying | Fuel pump |
| Just suddenly cuts out, no warning | Crank sensor or ignition switch |
| Will not restart even when cool | Different problem (battery, fuel, no spark) |
| Stalls + check engine light | Pull codes for direction |
Tell us your symptoms and any codes. In under 60 seconds you'll get a step-by-step diagnosis tailored to your car, the parts you need, and what a fair repair should cost.
Get My Repair Report →Cheaper than one wrong part. Backed by mechanic-trained AI.
If your scanner is showing one of these, that's your starting point. Tap any code for full causes and repair costs.
Heat-soak failure. A part that works cold (cool sensor, healthy resistance) fails at full operating temp (hot sensor, high resistance). Once it cools, it works again.
Check what is hot near the stall. Crank sensors on the back of the engine, coil packs on top, fuel pumps in the tank. Pull codes during the stall.
Yes, eventually. Each stall takes longer to recover. Fix before it becomes permanent or before it kills the battery from repeated starts.
Less likely with this exact pattern. Alternator failures usually cause battery light first and progressive electrical drain, not a clean cut-out.
Drive in short trips before it stalls. Avoid highways or long drives until fixed. AAA membership is worth it now.
Crank sensor: $80-$350. Fuel pump: $400-$1000. Coil: $80-$300. Ignition switch: $150-$500. Diagnose with a scanner first to avoid wrong-part replacement.
One $5.99 report can save you from a $400 wrong-part install. Our AI walks you through the exact diagnosis, in plain English.
Get My Repair Report →