Engine Shaking When Starting Car

Causes of Engine Shaking When Starting Car

There are several possible causes of engine shaking when starting a car:

Bad spark plugs: Worn or fouled spark plugs can cause the engine to misfire, which can lead to shaking.
Bad ignition coils: Faulty ignition coils can also cause misfires.
Vacuum leaks: A vacuum leak can allow unmetered air into the engine, which can cause the air/fuel mixture to become too lean. This can lead to misfires and shaking.
Fuel injector problems: Clogged or malfunctioning fuel injectors can cause the engine to run lean or rich, which can also lead to shaking.
Engine mounts: Worn or broken engine mounts can allow the engine to move excessively, which can cause shaking.
Transmission problems: A faulty transmission can also cause the engine to shake.

Diagnosing Engine Shaking When Starting Car

To diagnose the cause of engine shaking when starting a car, you will need to perform a few simple tests.

1. Check the spark plugs. Remove the spark plugs and inspect them for signs of wear or fouling. If the spark plugs are worn or fouled, they will need to be replaced.
2. Check the ignition coils. Inspect the ignition coils for any signs of damage or corrosion. If the ignition coils are damaged or corroded, they will need to be replaced.
3. Check for vacuum leaks. Use a propane torch to check for vacuum leaks. If the engine idle speed increases when you spray propane around the intake manifold, then you have a vacuum leak.
4. Check the fuel injectors. Use a fuel injector cleaner to clean the fuel injectors. If the engine idle speed improves after using the fuel injector cleaner, then you have dirty fuel injectors.
5. Check the engine mounts. Inspect the engine mounts for any signs of wear or damage. If the engine mounts are worn or damaged, they will need to be replaced.
6. Check the transmission. If you suspect that the transmission is causing the engine to shake, you will need to have it inspected by a qualified mechanic.

Repairing Engine Shaking When Starting Car

Once you have diagnosed the cause of engine shaking when starting a car, you will need to repair the problem. The repair will depend on the cause of the shaking.

Bad spark plugs: Replace the spark plugs.
Bad ignition coils: Replace the ignition coils.
Vacuum leaks: Repair the vacuum leak.
Fuel injector problems: Clean or replace the fuel injectors.
Engine mounts: Replace the engine mounts.
Transmission problems: Have the transmission inspected and repaired by a qualified mechanic.

Preventing Engine Shaking When Starting Car

There are a few things you can do to prevent engine shaking when starting a car:

Regularly maintain your car. This includes changing the oil and filter, spark plugs, and air filter regularly.
Avoid using cheap gas. Cheap gas can contain impurities that can damage your engine.
Drive your car regularly. If you don’t drive your car regularly, the battery can become discharged and the engine can become sluggish.

By following these tips, you can help prevent engine shaking when starting a car.