I am the proud owner of. 2007 F150 Lariat 5.4. It has new brakes all the way around, new shocks/struts, new transmission, basically new tires, new evap purge sensor, and several new coil packs. Now it has an inconsistent vibration. Sometimes the shudder is at lower speeds and stops at higher speeds and sometimes it’s opposite. Sometimes it doesn’t do it at all and sometimes it does it all the time. It also has new cv axle on the left. Driveshaft and u-joints are good. As of noon today, it’s not throwing any codes. I’m at my wits end. Any suggestions?

 

Did it do it before all of the new parts?

 

No. The new parts have been put on at different times but this only started a few days ago.

 

have you cranked any curbs lately or large pothole possibly bent a rim or tires un balanced, maybe lost a weight on rim..

 

I had all the tires rotated and balanced about a month ago. They are only about 4 months old. It started while on smooth interstate. I really think it’s a miss causing it, but it’s the dreaded spark plugs that tend to break when taking them out.

 

how about servicing the rear differential? Also if you take steps in advance such as pb blast in your spark plugs a few times and miles before you even pull them, with an impact gun you should be able tonzip plugs out relatively easy when they are hot provided you spray them few times before and apply a constant torque to remove

 

Had the truck looked at today and definitely one spark plug causing the issues. It did break while coming out but they got it replaced. Runs and drives like a new one now.

 

I have a 2014 f150 Platinum and I'm experiencing the same issue. Been back and forth to the dealer only to leave more frustrated. The spark plug issue solved it??

 

I had all 8 spark plugs replaced and it solved the problem. It runs and drives like a new one now.

 

Thank you, that was driving me crazy.