Transmission Behavior after new plugs and coils – 2011 F-150 Lariat
What is your question?
I recently replaced the spark plugs and ignition coils on my 2011 Ford F-150 Lariat (5.0L V8), and ever since, I’ve been noticing some odd transmission behavior and cabin feedback.
• Gear Shifting: The truck seems to be shifting through gears unusually early. For example:
o At 20 mph, it’s already in 3rd gear
o At 30 mph, it’s in 4th
o At 40 mph, it’s in 5th
o Sometimes at 30 mph, it’ll jump to 5th, and at 40–45 mph, it’ll go into 6th
This feels off compared to how it used to drive, and the shifts seem premature for the load and speed.
• Cabin Noise & Vibration:
• There’s a noticeable increase in cabin noise—almost like amplified road noise from oversized tires, though the tires haven’t changed.
• I’m also feeling subtle vibrations through the steering wheel and gas pedal, especially during acceleration.
No warning lights are on, and the truck starts and idles fine.
How long has your 2011 Ford F-150 had this problem?
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Hi - I am Dave, contributing to RepairPal and providing expert advice since 2010.
Your question describes your concern very well. I have to admit that having hands-on testing at a shop near you with an experienced technician who can determine what is going on from a road test that will experience the same things that you are describing. It's too hard to guess.
I also have questions, such as, where did the coils and plugs come from? Are they original Ford parts? Very important to know..
Reach out to a shop near you and feel free to respond in this forum for further information that may make sense as to why the problem is occurring..
https://repairpal.com/auto-repair-near-me
Click the link to find some shops near you who can help out!
Thanks Dave. The spark plugs are own -motor craft from Auto Zone. Coils I believe were off Amazon.