Guy's I know this may sound stupid but how can I tell the difference between a knock and a ping (other than the obvious)? I have a 99' F-150, 5.4 4X4. Truck doesn't have the power it once had maybe due to age (112,000 miles) but I maintain good service on it. I have tried tune up (plugs, fuel filter etc.) didn't help. Had bad O2 sensor replaced. Replaced collapsed vacuum hose. Engine knocks or pings up hills. It really sounds like valves rattling (maybe it is). I checked MANY posts but really not sure what problem could be. Any suggestions? THANK YOU in advance!!!!

 

Sounds as though you are experiencing pinging of the valves. Several things can cause this and there are probably more experienced people around that can give you better advice. With the stated mileage I would guess you might have jumped timing or your timing chain may have gotten stretched over the years. The easiest thing to try IMHO is to bump up to the next higher grade of gas (unless you are already using premium of course) and see if that helps after a couple tanks full. In older models the timing could also be retarded, but with the newer computer controlled spark timing the computer should take care of that automatically. If the gas change don't help go get a diagnostic check, which can usually pinpoint most, if not all, of the problems one has with the more modern engine and sensor set-ups.

 

There is a possiblity of the knock sensor could be going bad, do a search on this word and it will give you more info, these 5.4's are a pretty stout engine and more often it is the sensors that will give you the most trouble

try this link for more threads on this.

https://www.ford-trucks.com/forums/s...earchid=155701

 

A ping is somewhat intermittent. A knock sounds like a washing machine full if marbles.
My 98 has over 125,000 and does neither. Try some intake/fuel injector cleaner. I like chevron with techron personally. Carbon build up, lean condition, and incorrect timing are the main culprits.
Knock sensor would have the biggest effect on timing when the engine is at operating temp. I believe there are two of them. The installation torque for each is critical to its function.
Lean is either unmetered air such as a vacuum leak or dirty MAF. It could also be low fuel pressure.

Any CEL? Have an autozone or other parts house check for stored codes.

Also Welcome to the forum.

 

Here's a link to some good info.
http://www.streetrodstuff.com/Articl...ne/Detonation/

You can Google the terms (preignition, detonation, etc) there's lots of reading out there on the subjects.