I have a 97 f-150 with a 4.6. It has always had a loud ping coming from the drivers side it sounds like. Now, it only happens at around 4000 rpm under load. I know the egr ports are clean, the throttle body is clean and the rest of the truck is very very well maintained. I have run some fuel system cleaner through it but I can't get it to go away. Now I know what some of you are going to say, " don't rev it to 4000 rpm" well I live in colorado, and going up some of the mountain hills here with a load in the truck can be torture on my little 4.6. The truck runs great other wise. Just hope some of you have some ideas. Thanks!!!!

 

What octane fuel are you running? My 98 4.6 liked to ping under load if I ran anything less than 89 octane.

Not sure if we had the same problem but it's worth a shot.

 

I live in colorado so the octane choices are 85 89 and 91. I just use the 85 since I don't get good gas milage and gas is so expensive now, I can't really afford to spend more than I do!

 

Should be at least 87. As the engine ages the octane requirement goes up as well.
If your running 85 then you know why it's pinging, especially hard pulling in the mountains.
Sorry about the cost but you gatta do what you gotta do if you want to change anything.
There's an old saying that goes like this ' if you do what you always did, you will git what you always got'.
Take care.

 

i think ford recommends 87 or greater octane...

 

They give us 85 octane because in the high altitude, the 85 acts as an 87. I will definitly try a higher octane and see what happens though. Thanks for the help!!!!

 

I have a 2001 150 5.4 and it will ping it i use 87, or less so i've been running 89, or 93 and it quit, but these gas prices are killing us with v8 engines.

 

Have the MAF looked at. If the baro reading is off then it needs to be changed.
I don't mean cleaning it, although it may help, but have it hooked up to a scan tool so the reading may be taken form it.

JMC

 

I cleaned the MAF and no more pinging on mine. There's a good "how-to" post here somewhere, sorry I don't have the link.

 

link...