I have a 2005 f-150 with about 145,000 miles on it. Lately, sometimes when I am accelerating slightly, the truck seems to have this clunking/hesitation feel to it. It seems to do it more around 40-50 mph, & will do it about 2-3 times. I'm no expert when it comes to cars, but it feels like a shifting issue. Any ideas? Thanks.

 

Plugs misfiring usually show up between 45 and 50mph on these trucks, how many miles do you have and when were the plugs changed last?

 

The plugs are fairly new. I have about 145,000 miles on the truck itself, but maybe only 25,000 on the plugs. You can feel it physically in the cab & steering wheel when it does it.

 

No codes yet? When you changed the plugs, did you change the COP boots and springs?

 

4x4 ?

 

Most likely COPS. When a code shows it will help with the trouble shooting.
If you don't have a code reader or tuner, go to a local auto parts store. They will read the code no charge.
The FPDM may also be the problem.
Need to drop your spare tire and look at this unit. Most corrode and split apart in about 5 years. Replacements available on Amazon for about $60 or about $100 at local parts stores.

 

Took up to Autozone & it showed no codes. It is 4x4. Any other suggestions? Thanks!

 

Just like others have asked, were boots and springs on the COPs changed with the plugs?

 

Can't remember if the boots & springs were changed with the plugs.

 

Pretty cheap to change them, may help out with your issue