dionysus19

I recently updating to a canned tune from SCT and am trying to find the source of a loud knock sound. It only occurs during a very hard acceleration when the boost pressure is greatest and sometimes occurs once, other times its two in quick succession. It also doesn't seem to occur from the same spot everytime. All this makes me assume its some sort of pinging or knocking/ignition/timing issue.

Anyone have any thoughts?, Sensor readings I should be checking? Tests I should be performing?. I am going to put in an octane higher than 87 when I get a chance and see if it diminishes.


2011 F150 FX4 Ecoboost

Sirikenewtron

Are you running the 87 tune? Dose the 'Knocking" sound like pops/clicks or a chain slipping? Have you noticed puffs of smoke out the exhaust in sequence with the sound?

I would definitely start with higher octane, It's always a good idea to run at least one level higher octane then the tune also (Running 87 tune, use 91 octane)

And last, dose it do it when running stock tune?

dionysus19

Yes I have the 87 tune. It sounds like a pop. The first few times I assumed it was a rock hitting from underneath, almost identical sound.

Martian

Throw an octane booster in there and see if that does anything. If it doesn't, return to stock and again, see if it goes away.

Sirikenewtron

Then I'd for sure try the highest octane you can find,
octane booster doesn't do much fwiw.

It sounds like you are getting detonation, very bad.

You may have gotten a tank of bad fuel, I've had this same thing happen to me a few times, same sound also.

dionysus19

I put 91 in the rest of the tank to achieve about 87 octane. But I noticed when setting the tuner parameters that I had set the global spark to +3 degrees instead of the default 3. I don't know exactly what that does but this was probably bad.

Sirikenewtron

Oh ya, that could have turned out real bad, I bet that was the issue.

nemosdad

Wait...what? What octane were you running before putting in 91? How the heck did you "end up with" 87? Do you mean about 89 octane?

maplelakeduckslayer

Sounds like you got very lucky. Confused by a lot of what you are posting. Global spark should be at zero and if you brought the octane up to 87 using 91 that's concerning. Can you clarify some of that?

Koolponycar

Need to add some E85 maybe to get the octane level on up. Return it to stock and run that tank out. Put right octane in and leave the global spark alone. Then reload and see how it runs.