I got a 97 f150 that seems to have spark knock, it sounds like marbles in a can, or like a arcing noise, at high rpms and sometime under load or when I accelerate fast

Thing I have done so far
Cleaned maf
Cleaned throttle body, I port was completely clogged and other was only about 5%
I've seafoamed 2 times first time was trickle it in the PVC at idle, and the second was holdin at 2000 rpms and adding it then shutting down and waiting 5 minuetes and started it up, smoked a little and I noticed a sparck knocked worse for a few seconds goin down the road, it probably released some crud

I did all that and it still seems to spark knock I put 91 shell v power in it and doesn't seem as bad I think there may be some 87 octane in it yet but it's almost unnoticeable with 91 or 93 octane in it

I'm stumped I dont know what else to do, I don't have any codes at all, no cel, truck seem to run fine it's got a lot of pep to it, thing can even break the tires loose just from stomping I off the line, pretty healthy so it seems but the noise is there, I can only hear it when I got the windows up and the radio off

 

Read this thread for some ideas:

https://www.f150online.com/forums/19...4-pinging.html

Very possibly EGR-related.

 

When I cleaned the tb I checked the egr and it looked clean, I can test it when I get some time but I don't suspect to be the egr as I have no codes popping up at all

 

Neither did the poster in the other thread.

 

I tested the egr today by hooking a hose and sucking on the hose and the truck started to stumble rally bad so the function of the egr seems to be working

 

Welcome to the club . Up a hill at about 3000rpms under load and its marbles in a can no matter what. Ive had motorvacs done, egr system replaced/cleaned, throttle body cleaned, maf cleaned then replaced and no difference. New plugs and wires no difference. I gave up trying to fix it fwiw...

 

Yea if I accelerate fast it does it to, damn though that sucks, must just be something these motors just can't get rid of, it seems to run very well so I can't complain to much but just an imperfection that might not ever be mastered

 

What year is your truck?

 

Look at his sig.

 

Make sure the valley is clear, no coolant and that something wasn't dropped. The knock sensor is right there so your timing could be screwed.

 

Oh yea, specially magnets. I've lost magnets down there fishing for 7/8mm sockets.

 

I figured I'd add the solution to this problem since no other posts that I read do, my solution was/is run 93 or 91 octane, that's all that helps me, I've checked for vac leaks numerous times and found nothing So 93 octane does the trick until u can get codes or find the problem

 

You were given the solution and haven't capitalized.

So what comes next? - More problems I expect.

Hey man, it is what it is.

Live smart.

Good Luck.

 

Yup I run 93 octane in mine, always. Do the math its really not much more expensive when you figure it out the cost over one year.

 

Running high octane fuel in an engine not designed and tuned for it is a major waste of cash. jbrew pointed out the knock sensor. Your engine is telling you something. Pay attention.