I bought truck used it has a rough idle and sounds like a diesel u replaced cam sensor and the vct it seemed like it fixed it but now it's happening again any clue as to why

 

Is there a code?
The sensor is not all there is to the VCT.
If the cam gear is stuck fully advanced, the cylinder pressure for that bank can be excessive.
Good luck.

 

No code cam sensors replaced and the vct solinoids that are in the valve covers
My husband ain't no mechanic I'm the one who does the trouble shooting any ideas would be great

 

Cam phasers perhaps. Good video from youtube on the sound before and after replacement.

 

I've seen this vid after having the same issue with my 08, too bad my motor had totally failed before getting fixed, I've been told by my dealer that there's no fixing these issues once you loose all oil pressure

 

Having same sound as video on my 06 5.4. How much is it to have cam phasers replaced and is it a long-term fix or am I just buying time. Had thought about swapping motors instead of fixing phasers depending on cost.

 

Well I'm no expert here, but I did have the issues with my 08, researched a lot and found so many different opinions on what the main issue is, and how to solve, one posted video shows how easy it was to replace the phasers, then an expert commented - that only masks the problem, the real problem is the oil pump and the lack of oil getting to the top end at idle.
my 5.4 took a dump in the interstate at normal highway speeds, new Mobil 1 oil and filter, but my oil pressure dropped suddenly and sounded like the chains were rattling so bad.
the dealership told me, there's no fix once it gets to that point, which surprised my, I work on Harley motors, I know the twin cam setup is similar with the chain drive, when the tenioners go, the can be replaced and go on, so who to believe?
I had no choice and was lucky the dealership went in half for the re manufactured motor -
It's piece of mind for me, knowing I have a, what I think is a better than new motor, all the updates for that motor, and a 3 year unlimited miles warranty

 

Phaser issues can definitely be long-term fixed by following a few simple rules. Foremost - use ONLY Motorcraft Phasers, NEVER cheap aftermarket knockoffs. Phasers themselves are seldom the 'root' problem, so when you go in don't cheapskate the job - replace everything while there, (including rollers/followers if mileage is up there > 150-200k) and use ONLY quality parts. Do-it-yourself should hold parts cost less than $2,500 tops - even with misc. stuff. definitely less than engine swap.


Deciding to go for it is more nerve racking than doing the job. If you stay ahead of the major failure (chain jumping a tooth or serious DTC's) and just have diesel noise, startup rattle and rough idle, you can make a very informed decision by adding an aftermarket Oil Pressure gauge and run a good wet and dry compression test on all cyls. If lower end, rings and valves are OK, timing job should give you plenty more serviceable miles.


222k puts me 10K+ into my '04 5.4L timing job, burns practically NO oil (~1qt/2500 mi), and I believe it pulls/runs/performs as well as it did right after breakin. Fuel mileage is respectable (13.5ish all around city/urban/hwy).


Good luck

 

When doing a job of this magnitude, one should always check out all the elements associated.
Oil pressure is what drives the VCT function. It should be tested.
Cam chain tensioners, and it's tension-er piston seals checked or replaced.
The VCT gears replacement and timing procedure fully understood.
For the expense and labor of the job there should be nothing left to cause an early future failure from lack of attention that results in wasting the effort and expense..
The oil passes up through the block at the rear of the head on the passenger side through a filter screen, through the camshaft core to the front sensor.
The driver side oil comes up in the front to the phaser and through the cam to the rear.
The sensor, under control from the computer, gates oil and volume into the VCT gear changing it's phase timing with the crank.
Very often the phraser failure is due to poor oil change intervals.
At this point there could be some serious wear to the cam journals oil pump and other parts that cause lower oil pressure and leading to VCT system issues.
It's not a job to take lightly.
There is always an element of doubt that something has been left unseen , so some luck is in order with every job.
Good luck.