Loose, broken, or worn valve train component. Remove the valve cover to find the problem.
how much valve clearance triton 2,5.intake and exhaust ??
Inside the valve covers.
Common causes of a running toilet include a faulty flapper valve, a worn-out fill valve, a leaky flush valve, or a problem with the float mechanism.
Cam Bearings
the valve cover gasket!
Noisy valve train. Remove the valve cover and inspect the valve train.
If any car backfires it is usually due to retarded timing, running lean or a problem in the valve train.
Worn valve train starting with the camshaft lobes.
It can be a number of things, but the most common problem is worn valve guides.
The most common problem would be a valve lifter not pumping up. Of more concern would be the valve seat in the #4 cylinder going bad. Escorts have had this very common problem for years.
Ford started using the 5.4 L - 3V in the 2004 model F-150