Hello & Good Afternoon:

I am new to this Forum. My name is Ben. I love my 2004 V8 F150 Fx4 Supercab. I have 101,500 miles I have logged since 2004.

I am asking about a Check Engine Light that has now come on for the second time. The first time, a mechanic with a computer checked the codes and it read P0303 (those are zero's) cylinder 3 misfire & P0316 mis-fire on start up. The lights have probably come on a week apart from each other: today being the second time. The temperature has been real cold outside. Each time the check engine light came on I felt a roughness in the idle. It felt like it would go away once I started driving though. Almost like a bucking or rumbling when not in gear yet. Maybe a little while in gear now that I write about it. Today I was on the highway and stepped on the gas to accelerate quickly and the check engine light started to blink many times then went back to "just on". I only remember one time since light came on that the truck had me feel like I was going to break down. Please help me! All advice can probably/hopefully save me money with the mechanic. Since like all of us, I'm on a very tight budget.

I thank all of you who read this message and have advice!

Thank You
Ben

 

Have you ever changed your spark plugs or checked your coils yet?

 

I replaced spark plugs at 95,000. I'm not sure about coils. What would coils cost, do you know?

Thank you for reply to post!

 

Hi and welcome.

Those are indeed misfire codes. There is a LOT of information posted on this - even recently.

You can find Visteon COPS online for a couple hundred dollars for a set of eight. A dealer of parts store will charge you more. Use only Motorcraft or Visteon COPS - or else risk future problems from low-quality alternates ( Accel among them). COP # is DG-511.

Do you know which plugs were used when they were changed? Was dielectric used? New boots? Current plug revision is Motorcraft SP-515.

As a quick test - move COP #3 to another cylinder. If the DTC changes to that cylinder, it's the COP - if not suspect the plug (or injector).

good luck
MGD

 

Thank you for the ton of information! I'm not mechanically inclined so I don't know the terminology you used but hope to get a friend who might. I'll write down your advice to have checked out. I will research the areas in your post to help navigate me.

Thanks, Ben

 

My receipt from Spark plug change does not say the brand that was used. I could ask the mechanics who did job, tomorrow.