Hello all,
So my '04 f150 stx 2wd 4.6 v8 is running a little rough at idle, noticeable every few revolutions of the engine. Extra noticable with foot on brake and able to feel vibration from engine through pedal. No dash lights or codes present.
Recently asked my regular mechanic to take a look, and he said the cannot pinpoint which spark plug/coil it is un until it gets worse, and throws a code.
What's your thoughts on narrowing this down faster? Thanks
Oh, and the truck is grey if that helps ���� ( I know it doesn't, , haha)

 

The auto enginuity software should be able to pin point. You may be able to have it running and unplug each coil pack while idling and see if it gets worse or stays the same. When is the last time the plugs and boots were changed? It could even just be a cracked boot causing an arch and miss fire.

I know Bender chased it on his truck for a while.

Another way would be to purchase one coil and swap it around unitl it smooths out, but I would also pull and replace all the plugs.

 

I found 8 coil packs on Amazon when my wife had the mountaineer and replaced them all, and everything smoothed out. I thought $35 for 8 coil packs meant that they were all going to fail in a week, but they lasted two years until she sold it.

 

Make any progress on the miss?

 

This is generally how I handle it as well. Auto zone sells ask 8 pack lifetime warranty, but you could buy two of Mike's link and just have spares....

 

I have not made any progress on this engine miss , toyman. I have been considering getting a second mechanics to scan it before I drop the money they want.
But havent had the time.