Why can't the hot car motor turn? Analyze common causes and solutions
Recently, one of the hot topics in the field of automobile maintenance is "difficulty starting a hot car", especially the problem of "the hot car motor cannot start", which has triggered widespread discussion. This article will combine the hot content of the entire network in the past 10 days and provide you with a detailed analysis of the causes and countermeasures of this phenomenon through structured data analysis.
1. Common reasons why the hot car motor cannot rotate
| Ranking | reason | Proportion (discussed data in the past 10 days) |
|---|---|---|
| 1 | The battery is insufficient or aging | 32% |
| 2 | Starter motor carbon brush wear | 25% |
| 3 | Ignition system failure (spark plug/coil) | 18% |
| 4 | Insufficient fuel pump pressure | 12% |
| 5 | The engine has serious carbon deposits | 8% |
| 6 | Other reasons (line/ECU failure, etc.) | 5% |
2. Fault phenomena and corresponding diagnosis methods
According to the recent cases compiled by the auto repair forum, there are obvious differences in the performance of faults caused by different reasons:
| Failure performance | Possible reasons | Rapid detection method |
|---|---|---|
| There is a "clicking" sound when starting but the motor does not rotate. | Insufficient battery voltage/worn motor carbon brushes | Measure battery voltage (cold car ≥12.6V, starting ≥9.6V) |
| The motor rotates slowly and weakly | Battery aging/poor circuit contact | Check whether the battery pile head is oxidized and test the voltage drop |
| No response at all after heating up the car | Motor thermal decay (coil/pole failure) | When the car is hot, tap the motor housing lightly with a hammer to test. |
| With the dashboard flashing | Main relay/fuse failure | Check the engine compartment fuse box |
3. TOP5 recent popular solutions
According to Douyin/Kuaishou auto repair short video data statistics, the following methods have received the most practical verification:
| solution | Applicable scenarios | success rate |
|---|---|---|
| Replace the enhanced starter motor | Vehicles that frequently travel short distances | 91% |
| Upgrade AGM battery | Models with automatic start-stop function | 88% |
| Install motor cooling cover | turbocharged engine | 79% |
| Clean fuel pump filter | Old vehicles more than 5 years old | 85% |
| Refresh ECU program | New electronic throttle models | 68% |
4. Preventive maintenance suggestions
Combining the latest maintenance manuals of 4S stores and the experience of Internet experts, the following suggestions are given:
1.Check battery health regularly: Check the CCA value before winter every year. If it is lower than 70% of the nominal value, it needs to be replaced.
2.Avoid frequent starts of hot car: When the engine is at high temperature, the continuous starting interval should be >2 minutes.
3.Choose high-quality engine oil: High temperature viscosity index (such as 5W-40) must meet the manufacturer's requirements
4.Keep oil lines clean: Add regular fuel system cleaner every 20,000 kilometers
5.Upgrade wire specifications: Old cars can be replaced with ground wires of more than 25mm²
5. Special reminder from experts
Recently, many auto repair Vs mentioned in live broadcasts that although new energy vehicles do not have traditional motors, failures in the high-voltage battery preheating system can also cause similar phenomena. If a hybrid model experiences a delay in hot start, check the following first:
- High voltage relay contact resistance (should be <0.5Ω)
- DC-DC converter operating voltage (standard 12.8-13.2V)
- PTC heater circuit current (refer to service manual)
From the above structured analysis, it can be seen that the hot car start failure involves the cooperation of multiple systems. It is recommended that car owners use the OBD diagnostic instrument to read the fault code in time when encountering problems to avoid waste caused by blind replacement of parts.
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