Why does my car lose power for a second when starting?
A momentary power cut during ignition is typically caused by a failing ignition switch, a weak battery connection, or an aging starter solenoid that momentarily drops voltage under heavy load. This intermittent electrical blip stops you from knowing whether it is a harmless quirk or an early warning sign of a complete no-start leave-you-stranded failure.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 9.3× more often in r/MechanicAdvice than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Replacing the battery2 people mentionedDid this help you?
- 2Replacing the ignition control moduleDid this help you?
- 3Testing the battery and alternatorDid this help you?
- 4Inspecting exhaust manifold connectionsDid this help you?
- 5inspecting the starter visuallyDid this help you?
- 6taking the starter off to look insideDid this help you?
- 7attaching a video of the noiseDid this help you?
- 8Testing the batteryDid this help you?
- 9Checking if the battery terminal is looseDid this help you?
- 10Visiting an auto parts store to ask for a battery testDid this help you?
- 11Testing and cleaning grounds and terminalsDid this help you?
- 12Checking the starter relayDid this help you?
- 13Using a jump start when it slow cranksDid this help you?
- 14Disconnecting the battery briefly to resetDid this help you?
- 15Guessing potential failing components such as the fuel filter, fuel pump, or distributor capDid this help you?
- 16Checking battery healthDid this help you?
- 17Replacing the starterDid this help you?
- 18Inspecting ground connections and wiring harnessDid this help you?
- 19testing alternator, starter, or batteryDid this help you?
- 20checking fuel injectors or fuel pumpDid this help you?
- 21Repeatedly pressing the start button until the engine finally firesDid this help you?
- 22Shifting between park and neutralDid this help you?
- 23Rolling the vehicle out of the drivewayDid this help you?
- 24Getting a jump from a friendDid this help you?
- 25Replacing the battery assuming it is a power supply issueDid this help you?
- 26Taking the vehicle to a specialized workshop multiple times for diagnostic checksDid this help you?
- 27charging or replacing the batteryDid this help you?
- 28jumping the starterDid this help you?
- 29checking and cleaning electrical connections and battery terminalsDid this help you?
- 30testing the starter and inspecting battery cablesDid this help you?
- 31Testing battery voltage with a multimeter before and after a jump startDid this help you?
- 32Seeking diagnostic help from online mechanic forums to narrow down the causeDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“It seems like a battery or ground issue but I've tried replacing the battery and testing and cleaning grounds and terminals.”source ↗
“Car was starting and running fine until I let it sit for about two months. When I try to start it now this is all I get.”source ↗
“Tried charging the battery still weak crank.”source ↗
“I don't know enough to really diagnose it.”source ↗
“I haven’t no!! I don’t know how I would do that lmaoo😭😭”source ↗
“Im having the same problem in an 04 pt cruiser. Runs fine and randomly stalls coming up to a stop.”source ↗
“It takes an extended crack time to start the car but once its starts it runs without issue.”source ↗
“Not sure if it’s fuel filter, fuel pump or maybe even the distributor cap.”source ↗
“Car recently started having slow startups, like it’s struggling. Occasionally I will lose pedal power where I just can’t accelerate or even apply any power.”source ↗
“Recently brought my car in to the shop and replaced the serpentine belts. Went to turn on the car today and it started making this sputtering noise and now it’s happening every time when trying to start it. Also, the lights get dimmer when the car is idle and turns back to its original brightness when the engine is revved. Any ideas what the problem could be?”source ↗
“My car engine occasionally has trouble starting.”source ↗
“I have to try to press the start engine button anywhere from 2 to 7 times when this happens.”source ↗
“I have a 2009 Hyundai Sonata v6 with 160,000 miles, and starting about 2 weeks ago I’ve been having weird starter issues about 5-10% of the time.”source ↗
“Had a few more instances of no crank that would resolve after a bit of muscling and shifting between park and neutral.”source ↗
“Looking for confirmation before I spend that kind of money.”source ↗
“So my 2019 Honda HRV started doing with this yesterday😭 idk if it’s the battery or alternator if anyone has any idea!!”source ↗
“Having trouble diagnosing issues with a 2005 buick lesabre. 3.8 V6 auto. When turning the key, the power cuts off for a millisecond before starting and then the car runs fine.”source ↗
“Car starts perfect 95% of the time, but 5% of the time I can hear the starter spinning a but too long AFTER I startup.”source ↗
“Any one knows the source of this sound? Or what should it be?”source ↗
“I did check the battery last week and the results shows that its perfect 🤔”source ↗
“I think I'm going crazy with this car 😅”source ↗
“For the past 2 months I've been having this problem where the car would randomly lose all power when driving and won't start up again.”source ↗
“The car will start up after some hours or days like nothing happened.”source ↗
“I am desperate because since it is an intermittent problem it is difficult for a mechanic to notice since car will boot up again after having it stopped in the car workshop for multiple days.”source ↗
“recently it’s hard trouble starting, i cant afford to gamble on buying parts due to lack of money.”source ↗
“the issue now is starting it up it’s sluggish all over again and doing the same thing it did before completely going out.”source ↗
“i’m not sure if it’s the starter? maybe the battery or alternator.”source ↗
Where this came up
People with this problem also raised
- 168Vehicle cranks after fuel pump replacement but won't start
- 11Why does my car stall when I step on the gas?
- 16Car won't start or shift gears after dead battery
- 26Intermittent car hesitation with no trouble codes
- 2Why does my leaf blower start for 3 seconds and die?
- 74Why does my car make a loud rattle when starting the engine?