I have a 2006 f150. The last couple of weeks I have noticed my truck has had a bit of a rough idle. Then this morning I went to leave for work, it felt like a shudder or maybe a gear slipping from a dead stop. No noticeable slipping or rough running once I get going. It did it at a couple of stop signs then ran fine. No rough idle or shudder/ slipping . Any ideas?

 

How many miles on your spark plugs? Do you have a limited slip differential?

 

A lot of times those little fish bite misfires turn out to be a COP getting weak.

 

Honestly I have no idea how many miles on plugs. I bought the truck used. It has 105,000 miles on it. They could be the original plugs. I have read that changing plugs on these trucks is a pain. Wish I would have known that before I bought it.

 

Excuse my ignorance jcr . What is the COP?

 

But yes fish bite shudders is a perfect way to explain what is happening. I could not think of how to explain it. Thank you.

 

COP = Coil On Plug. Excessive spark plug gap is what causes them to get weak. Would you change the plugs yourself or would you have it done?

Do you have a limited slip differential? Look at the AXLE code on the door jamb sticker, it's 2 digits. If it begins with a letter it's limited slip. If it is, change the fluid, use 75W140 full synthetic and a bottle of XL-3 friction modifier from Ford.