CoachPoffy

Have an 05- 5.4l3V with 110,000miles. On a trip this summer noticed slow acceleration to HWY speed between 1800-2000rpm. Truck accelerates from stop good until about 1800rpm, then it bogs down and slowly keeps upping rpm until a little above 2000rpm when it picks up acceleration suddenly and goes back to normal. Runs good otherwise. Have noticed a different sound to the engine running. Its much louder. No exhaust problems or leaks. Sound is coming from engine. Just sounds like something is out of wack with timing or something. Not the normal hum of the engine with the typical tick of these engines. Happens cold or hot. Have noticeable sounds of engine throughout entire drive cycle. Gas mileage has dropped to 11.2 mpg according to computer. Replaced plugs, COPs, fuel filter, air filter, cleaned MAF. Oil changed regularly and have no evidence of sludge or burnt oil. What do we check next?
Any help appreciated as I am pulling my hair out and can't afford to get something different at the moment.

The loud six

5.4s have a very bas reputation for this it can be a number of things honestly if uve replaced the spark plugs, the next logical things would be timing chain service or the cam postion sensor

The loud six

i have a 4.6l v8 so i dont have these problems, but i have a guy i work with that has a 2006 4door fx4 with the famous 5.4 hes had it sense it was new hes had th etranny rebuilt and also did that list of things u did at 145k when his started this the stock oil guage wont tell u but him and a mechanic hooked an aftermarket oil guage to it and discovered it was dropping oil pressure so his 5.4 is done but when he does drive it it sounds funny like u say almost like it jumps timimg it runs bad and hesitates to go. the 5.4 is very famous for this. after the cam sensor or timming chain service or at least have it looked at the logical thing to do is trade it in 5.4s are badass before 100k then they have problems but however some dont thre are some that have 205k on them and never have problems but they all still have that tick. its just a freak thing dont take it to ford either they will charge you out the *** and not fix your problem.

johnny_tucson

Clogged cats? O2 sensors?

The loud six

thats also on the list of things it could be, but in all honesty if your cats were clogged or ur o2 sensors were bad ur engine light would come on, but i would always go with the cheapest fixes you never know

The loud six

ive seen these trucks on these forums starting this as early as 75k so its alla bout how u drive and how good youve kept up with matinence, however sometimes its unavoidable. thats just the 5.4 im sorry to say to people ik that have them.

johnny_tucson

You might also try the ecu relearn process.

The loud six

that is also on the 5.4 list. you take it to a mechanic that has delt with 5.4s before he will tell you that its a long list that gets exspensive quick and non eof them may be your problem. ford doesnt even know or at least the one thats near where i live lol

CoachPoffy

I thought about the CAT. Check on my scanner and the bank 1 #2 o2 sensor was fluctuating a bit more than the bank 2 sensor, so I replaced the bank 1 CAT. No difference. Read about the phaser issue which is where I'm leading to, but most of the posts say that the noise gets worse when warm. In our case its the same weather its warm or cold. We actually have less lag in accel when its cold, but the sound of the engine is still the same. Would changing the Cam position sensor or the VCT be next, or just dive into the entire CAM/timing chain/tensioner rebuild? Also, through this whole process, the truck has never thrown a code or misfired. Could the timing chain on bank 1 have jumped a link and that is what is causing it to run rich and sound this way?

supersky

Here's another thing to add to your list of things to check. Not sure if this will help, but it would only take a couple minutes to check.

https://www.f150forum.com/f4/bog-dow...solved-166431/