well we used to have a 98 expedition 4.6 and now i have a 97 f150 4.6 and they both had a bad ping when you ran regular octane. just wanna see if anyone else has the ping or did i get 2 bad cookies.

 

Were you running spark plugs other than the ones on your emissions decal? That will do it. Almost every Ford truck I have had to diagnose with this problem was cured just by putting the right motorcraft plugs in. Or new ones. If high mileage or contaminated by oil, gas additives or whatever they will ping.

Also on these engines, you need silicone grease inside and outside the plug boot, first to keep the moisture out, second to keep it from corroding.

 

My 98 f-150 4.6 ping on 87 octane.

New plugs and wire, probleme still present.

89 octane, perfect.

This funny **** began 4 years ago, when I fill it 2 time on supreme gaz.

now I cant go back to 87, its a dog and sound like crap, so 89 is ok for me

 

Is it all motorcraft parts you are using for plugs and wires, coils etc? Non factory parts will do it every time.

If you for some reason, put super in it then have this problem switching back, then unhook your batteries for a while then hook them back up. It will relearn a lot faster for the pinging that way.

When the knock sensor detects engine knock it will retard the timing and a few other things until it stops, After several times of this it should learn not to knock in the first place. Unless something is wrong. Usually non motorcraft parts.

I no longer work at any dealers. I just learned the hard way about this on mine and on hundreds of other trucks I have worked on over the years.
These cars anymore just do not like cheaply made aftermarket parts.
A couple years ago I knew I had a bad ignition coil on a VW jetta. I just knew it.
The owner wouldn't let me get the part at the dealer. I put on one from Napa instead. It didn't work. I tested it and everything was fine though.
Took it back and got another. Still no fire. Threw that one across the shop got one from carquest. No fire! By now I was about ready to set fire to the car. Took it back and got yet another one. NO FIRE!
Put the original one back on just for the heck of it and it worked.

I told the owner I didn't have a clue anymore and just take it but it should probably die again before you get home. He said ok whatever but I'm never bringing it back to you again. I said thanks!

It didn't make it home on him as I predicted. His tow company towed it to the dealer where their diagnosed it and came to the same conclusion. Bad coil. They put on a new VW marked one and it fired right up. Go figure.

A few days later when it kept running good the owner came back to me and said ya know you were right. It was the coil and only a factory one would work.

I was so mad I just shook my head in agreement with him.
He still brings that thing to me too. No aftermarket parts anymore either for him.

 

Uhm I would seriously doubt the trucks are meant to run on 85 or 87 octane. Please read your owners manual for the correct octane rating. Most the Triton engines are designed to run 89-91 octane.

 

A ford need motorcraft plugs, wires, coil, cap or rotor. I've done the job whit oem parts.

Everything else on engine ignition will do funny things, i dont know why, thats ford

On the next tank, i will put 87 and unplug the battery for 20-30 minutes.

I've tried many time to go back whit 87, even ford 2-3 weeks and its always same thing...bad ping and pull like crap. but never unhook the battery when i'm on 87

The truck is still doing good mpgI'll give it a try

edit: my owners manual says 87 octane

 

You can also try running a can of seafoam through the intake, that sometimes helps with pinging.

 

well, the obviously need higer octane if we had 2 fords with 4.6s that pinged with regular.

btw, what octanes do you guys have? we have 83, 87 and 93.