J.Manning

I have a 04 f150 with the infamous 5.4. It has has the "diesel" sound since it had 20000 miles (currently has 100000). When the truck is at hot idle (traffic light, etc.) The truck will start knocking and shaking and eventually stall if u do not hit the gas. Truck runs fine other than at hot idle. It used to do it once in a great while but now does it all the time. I was told cam phasers but it still does it if the solenoids are unplugged. Am I wrong to think that the phasers can't retard the cams if they are unplugged? I have cleaned the throttle body and changed my oil (using 5w20 motorcraft oil and motorcraft filter). Any ideas would be appreciated. I don't want to spend a ton of money without having a better idea what is wrong. Thanks

gforceman

Replace phasers chains guides and tensioners . I did and cured my noise .. found I had a blown tensioner seal on left bank causing a low oil pressure on that phaser


Or read here. >. https://www.f150forum.com/f4/final-r...-sound-141266/

J.Manning

Do you think I would have to also replace the VCT solenoids?

alsatropine

iTrader: (2)

While you are tackling that job, it might be a good idea. Go to fordparts.com and search for a Engine Variable Timing Solenoid. Click Dealer availability. You should be able to buy them for around 50 bucks a piece but call the dealer first and verify that it is the correct price. It would also be advised to order the seals that go into the valve covers also. They are about 12 bucks total for both of them. I just did mine with 183000 miles on it along with timing chains, tensioners, and everything. Helped a whole lot with the noise. There is a change in the design of the vcts. Hope this info helps a little bit.