I have a 2005 f150 that i just bought.its a 5.4L V8 It shakes while idling and while accelerating. Barely shakes when im coasting(not pressing the gas) The person i bought it from said the engine was shaking because it needed a tune up. I brought it to pep boys and they told me that they would have to take my engine cap off (which is aparently a big deal and at least a day of work) just to figure out what the problem was and that its nothing a tuneup will fix. I personally think they are just trying to get money out of me. Its throwing 3 engine codes:
1. System too lean bank 2
2. Cylinder 8 misfire
3. Engine misfire detected at startup
I just got this truck yesterday under the impression that i just needed to do a tuneup on it and now im being told that its gonna be at least $500 just to figure out what the problem is!
From what i can hear, the shaking noise is the loudest on the right side of the engine(if you are looking at it from the front of the truck) its a pretty bid shake though so its concering. Its also definitely not using all 8 cylinders. My old 4cyl civic picked up speed about 10x faster. It has 160,000 miles and i have no idea what has or hasnt been done to it because it was a repo. Im looking to skip the figureing-out-whats-wrong-with-it part. Does anybody know whats wrong with my new baby?

 

Take it to a Ford dealer - and it will probably cost you at least $500 by the time you are done. It probably needs new spark plugs and one or more coils.

Why on earth did you buy it when it was running that bad without having a professional look at it first? Buyer beware!

 

Because i also thought it was the spark plugs. And its a 2005 f150 Fx4 lifted, fender flares, bullbar, toolbox and leather seats for $6,200 so i figured it wouldnt be an issue if i had to fix a few things. No regrets. If i have to spend $1000 i will be okay with that.
A few of my friends have said it might be the lifters

 

What about if it needed a new engine, would it still be worth it? The 5.4 can be problematic with a lot more than just plugs sticking. Especially since you have an 05.

Not trying to be negative, but research and having the truck looked over goes a long way if you don't know what to look for. I don't like seeing people get burned.

As stated, take it to a ford dealer. Pep boys isn't a good option.

 

And what if it doesnt and i spent $6200 on a gorgeous truck and $500 fixing it. And if it needs a new engine then it needs a new engine. Not too worried about it. I just wanna know whats wrong with it

 

Very well. Then bring it to a ford dealer.

 

Im on here to try to figure out what the problem is without having to spend a ton of money at a ford dealership

 

I'd start with a plug change and look for a vacuum leak for that lean bank issue. If it still misses on #8, then swap coils with another cylinder to see if the miss moves.

But, you need an experienced mechanic to diagnose it correctly rather than throw parts at it. It might be cheaper in the long run to pay the price for the dealer to diagnose it. All we can do on the board is wild guess as to the problem(s).

 

There are so many things that can go wrong with a 5.4 3 valve that I think you would really be best served by taking it to Ford for a competent diagnosis. It is not a simple engine by any means. A backyard mechanic with no experience on 5.4 3 valves doesn't have a snowball's chance in hell to diagnose it correctly.