marauder11

2012 F150 ECO XLT
3.73 rear end
43000 KM

Well i got the shudder today. I had gone to pick up my brother inlaws boat for him. On the way home i was going up a hill and the RPM went up to around 2500 and i started to shudder. I noticed that i could get it to happen again right at the 2500 RPM mark. The truck ran fine while on cruise and around the 1500 mark till i would increase RPM than it would do it. I made this happen 3 times total as i have heard a misfire dumps fuel in cats and can wreck them.. I am guessing the plugs need replacing as i have never had a issue . When it is light out i will check for a cracked plug. Still am going to send to the dealer.

I have a video just can't figure out how to post it yet

MadocHandyman

Ya, sounds like a bad coil or plug.
Keep us posted.

brucesears

43k KM, if the plugs have never been checked it's time. They need to be replaced or regapped about every 20-25K miles. Especially if you're tuned.

marauder11

No tune.

marauder11

Here our pics of the first plug on driver side closes to front. I am not sure the cylinder layout. If anyone can help me on that i am wondering which one is 4. the box is the replacement the dealer gave me

papa tiger

Seems the iridiums opened up a lot.

marauder11

yup measure 40.. New one are at 30 already .

marauder11

Just finished doing a test after the plugs replaced. WOW is all i can say. That is the truck i remember. I actually believe over the long run it was losing some get up and go. What a big difference. Thanks to all previous post on this subject..

MadocHandyman

Good to hear!
I've just hit 90000 kms, maybe I should consider doing mine very soon.

itguy08

I don't think they did the changeover to the Iridiums until the 2013's so you may have had the plainums in the truck. Can you post the part # from the plugs you took out?

It is amazing how these engines do much better on new plugs!