Hey guys.

I recently got the code P0305 on my 08 F150, and yes it has the 5.4l.

So far I've checked the coil, switched it with cylinder 6, no change, checked the spark plug, seemed "OK," and tried to put a Champion plug in just to see if that would make a difference, again no change....

So I'm at a loss. I had the timing done less than 1.5 years ago (stock Ford phasers, timing components, but with the Mellings high volume oil pump and pickup tub), plugs done about 5 years ago (stock Ford spark plugs)... I'm assuming this is a timing related job.... or am I crazy?

Ford did do the timing and it is still under warranty but any help would be greatly appreciated.

 

no need to introduce new parts, until proven out. Id put motorcraft plug back in, but swap cylinders (to double check it’s not a bad orig MC and a bad aftermarket plug). If results don’t change. Then pull injector and swap it with a different cylinder. Be very diligent checking details when you swap: visual inspection, wire connections, plug torque, etc Retest.

report back with results.

 

Are you moving boots with the coil. Is the plug torqued to 25 foot pounds . are all the connectors locking on cops and injectors , clean all cop tabs scrape and contact cleaner . You could have thrown a roller , I did it sounded bad . You may have to see by using noid light on bad cyl is it getting pulse. Lots of countfiet plugs

 

I'd vote for water got into the hole or something like that.
could have possible spit out a cam follower.

If it was a phaser or timing I think you would see misfires on the whole bank, not just one cylinder.

 

Not trying to argue but if it was a "bad plug" wouldn't this have happened earlier on? As for pulling injector that might be a bit more than I'm willing to attempt.

 

As far as I could tell, I was switching the whole thing. As for dropping/throwing a roller wouldn't that be something that Ford should have checked when they did the timing?

I dropped the truck off with Ford... they did the last bit of major work and there is a warranty, I'll let them diagnose and fix it.

 

good luck. Please post back with what they find, and what they charged.

 

Will do. I hope I don't get destroyed to much by this, it's the first "real" issue I've had since buying this truck.

 

After swapping parts, why not start with the worst possible scenario, take a compression test, then work backwards?

 

Wanted to give an update. Ford found the 2 coils had failed.... apparently wasn't cylinder 5, had all the spark plugs done as well.

Truck runs great! Thank you all for the help you provided!