Why does my 2023 Honda Accord Hybrid rumble or shudder when the engine starts?

Short answer: A hard rumble when a 2023–2025 Accord Hybrid's gasoline engine starts is often a fuel-injector problem. A light blip can be normal. Get codes read and ask Honda to inspect the injectors under warranty.

Symptom: A rumble, shudder, or vibration when the gas engine starts, a rough idle, or a misfire light, especially after the car has been running on electric power.

What to check first

1. Notice whether the shake happens when the gasoline engine starts after EV mode, or all the time.
2. Get codes read. A misfire code (P0300–P0304) supports an injector or ignition problem.
3. Ask the dealer if they have seen injector campaigns or technical guidance on 2023–2025 Accord Hybrids.
4. Do not ignore a violent shake — it can damage the catalytic converter if a cylinder is misfiring.

Likely causes

1. Failing fuel injector. On the 11th-generation Accord Hybrid, a strong rumble or shudder when the gasoline engine starts (after running on electric) is a pattern owners and dealers have tied to fuel injectors. Some cars also get new spark plugs at the same time.
2. A mild shake when the engine restarts that is normal. A brief, light shake as the hybrid hands off from electric to gas can be normal. A violent rumble, a misfire, or a check-engine light is not.
3. Spark plugs or another misfire cause. If injector work does not stop it, the dealer should look at plugs, coils, and fuel trim instead of stopping at the first guess.

What it usually costs

These cars are under factory warranty, and injector or plug replacements that Honda accepts as defective should be covered. Owners in these threads were dealing with the dealer rather than posting an out-of-warranty price.

Is it safe to keep driving?

A mild restart shake is common on hybrids. A violent misfire can leave you with little power and can overheat the exhaust. Drive gently to the dealer or have it towed if it is shaking hard.

DIY or shop?

Not DIY. Injector diagnosis needs a scan tool and Honda procedures.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the Honda Accord: 23V858000 (2023-2023 model years, fuel system, gasoline:delivery:fuel pump); 24V763000 (2023-2024 model years, fuel system, gasoline:delivery:fuel pump). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: NHTSA's complaints API returned no data (HTTP 400) for Honda Accord 2023–2025 when queried 2026-11-08, so no complaint count is available. This counts complaints that mention these words. It is not a defect finding.

What owners report

• In Bad engine rumble/vibration when transitioning from battery on hybrid on Reddit r/11thGenAccord, an Accord Hybrid owner described a bad rumble and vibration when the car transitioned from battery power to the gasoline engine.
• In Engine rumble on Reddit r/11thGenAccord, another 11th-generation Accord owner posted about an engine rumble, adding to the same complaint.
• In Fuel Injectors/Fuel Pump on Reddit r/11thGenAccord, owners discussed fuel injectors and the fuel pump on these hybrids, the parts dealers have been replacing for the shudder.
• In I have a '23 hybrid sport, and it's starting to "shudder" when I turn it on. on Reddit r/accord, a 2023 Hybrid Sport owner with about 32,000 miles said the car had started to shudder when they turned it on and asked what it might be.

Quick tip

If you're shopping for an Accord Hybrid, notice whether the engine start from EV is a light blip or a real shudder. Those are not the same thing.

Vehicle focus: Honda Accord Hybrid (2023–2025, 11th generation). Gas-only 1.5T and 2.0T Accords are different powertrains.

Safety / mechanic note

A misfire can cause a loss of power in traffic. Verify with a mechanic.