Why Does My F-150/F-250 Truck Shake?

Are you having trouble with your truck shaking even after you’ve had your wheels balanced and had your alignment checked?  The real problem could be under your hood.  Your engine needs oxygen to perform properly, and there are a number of things that can happen to the delivery of fuel, its ignition, and the mixture of gasses and air in the combustion chamber that can cause your engine to vibrate and shake your truck.  Check out the video above for a more visual explanation of these steps.

There are a few different things that you can check on to diagnose and fix the possible issue.

The first step is to check your spark plugs.  One or more of them could be misfiring.  You are going to be looking for worn or broken firing tips on the plug.  If you use a diagnostic tool, it can tell you which plug is misfiring.

• When the engine has cooled down, gently pull the red locking tab on the spark plug power plug up to unlock the release.  Press down on the black release tab and slide the power plug straight off of the ignition coil.
• Remove the single bolt holding the ignition coil in place and pull the ignition coil up and out.
• Use compressed air to blow out any dirt or debris that may be sitting on top of the exposed plug.  You don’t want it falling off the plug and into the engine when you remove it.
• Using a 5/8 spark plug socket with the 6 inch extension and 3/8 drive wrench, loosen the spark plug by turning it counterclockwise.
• Check the spark plug; place it back in or replace it if needed.

The next step is to check/replace the fuel injectors.  Clogged or dirty fuel injectors can cut the performance of your engine.  Before you check them, make sure to depressurize the fuel system and disconnect the battery.

• If you have it on the passenger side front foot panel, use the cut-off switch to depressurize the fuel system.
• Simply remove the plug.
• Remove the electronic plug from each injector, then lift the end of the fuel rail nearest the front bumper and pop each injector free.
• Check your injectors. Look for clogging from dirt, old fuel, and carbon build-up.
• If you need to replace any, make sure you lubricate the O-rings on the new ones with engine oil and place it on the end of each injector.
• Insert all new injectors into the engine hole and push downwards until they are seated properly.
• Reverse the removal steps and reconnect the battery.
• Start the vehicle to confirm installation.

Next, check for vacuum leaks.  This could impact performance.

• Spray soapy water on various hoses where you think the leak might be happening.
• If you see bubbles forming anywhere, then you have found the leak.  Change any hoses that are leaking.

The last step is to check the EGR valve.  The Exhaust Gas Recirculation valve sends combustion gases back into the combustion chamber for cleaner emissions and better performance.  The engine has to be running to proceed with this step, so be very careful.

• Remove the vacuum hose from the EGR valve.
• Ask a helper to pump the gas pedal, and get your vacuum pump ready.
• Once the engine starts to idle, attach the vacuum pump to the EGR valve.  As you turn on the vacuum, the engine should idle roughly.  It may even stall.  Apply the vacuum again, and hold it for 20 seconds.
• The vacuum pump gauge’s needle should be staying steady.  If it isn’t staying steady, check that the vacuum hose is connecting the vacuum pump to the EGR valve and is making a tight connection on both the valve and the vacuum pump..

If the engine idle grew worse when you applied the vacuum pump, and the vacuum pump’s gauge needle stayed steady, then this indicates that your EGR valve is working properly.