2001 Ford e-250. Engine_size = 5.4 Triton V8.

Question = no power. Started slowly at first. I felt it shift onto OD on a slight incline at first that it never did before over a few months. Now i get the finger because i cant get above 40 unless i am going down hill.

I have own this van since new. I have 276000 miles on it same belt same exhaust system.starts fine at low speed in town seems OK. help!

Answer: If it is misfiring, then the first thing would be to do a complete tune up with spark plugs, plug wires, inspect the ignition coil, etc. but it does not sound like the case. The engine would be shaking, not just having no power.  It sounds like you have 1 of 2 possibilities. First, low fuel pressure. Fuel pressure slowly getting worse over time will give the problems you describe.

You should change the fuel filter and then have pressure checked. It may be OK when at idle, so you may need to drive with it in view. Usually tape on to the windshield works. The other is a plugged catalytic converter. These also get worse over time and at higher speeds / engine loads. A backpressure check on the exhaust should be done, or disconnect the exhaust before the converter to see if it runs and accelerates better. And it WILL BE LOUD !

F-150 Triton Knocking

F-150 2006 Triton 5.4L 3 valve After twenty minutes of driving a beeping or buzzing sound is heard, then the rockers start knocking and oil gauge deeps to low. If i turn off the motor for a minute or two i can resume driving for a short period until it starts again. What's going on? Any help in this matter would be greatly appreciated.

Answer: You are loosing oil pressure to your Triton motor. This can be because of a plugged oil filter, extremely low oil level or it is contaminated. Change your oil first thing and see if that helps. When it is draining, look at it. See if it looks milky or some other strange color. If it is then you have an other problem causing this one. Leaking coolant into the crankcase is the most common.