Koolponycar

Ok, thanks. I currently have ran the mix down to mt and put 93 100% gas in tank. Going to see how it runs on that, even before I drop a tune in.

Koolponycar

I read in a 2014 manual that says: not to be concerned for occasional light knock at times.
Sounds like mine. So maybe this is a normal gas related issue. As long as its not through the entire rpm band.

Venuspie

iTrader: (1)

Got mine back yesterday and dealer found nothing. They reset my kam (keep alive memory) and said everything is normal. I will run a few more tanks of 87 through it to see if it straightens out.

Koolponycar

Looks to be more common with the 5.0 than not. I have a X4 tuner and it has the KAM reset ability too. I tried that and Im sure they did to at my visit. Of course I ran some E85 though my tank first and I tell you my truck had more power stock down low for sure. I am planning a trip around thanksgiving and I think I will use E85 up there and back just to give it a better cleaning. Truck is running fine on the 100% 93 at this time.

Venuspie

iTrader: (1)

Well still no fix. Knocking louder than ever! Dealer says next available spot is a week from Monday! Looking for a less "busy" dealer. Have gotten gas from 3 different stations and added a bottle of sea foam. No change. Haven't ran E-85 in the last 4 or 5 fill ups. Just 87 octane. Not sure what to do!

Koolponycar

So you have a audible knock, not just occasional ping/spark knock?

Venuspie

iTrader: (1)

No. It is just an occasional spark knock/ ping that I can duplicate anytime by putting the engine under a load. Cruising downhill or any other relaxing time for the engine is fine. It is spark knock, I know it well from my past of mustangs and turbos with too much timing and blown head gaskets. I used to turn a lot of wrenches myself but gave it up.

Koolponycar

I ran 100% real 87 gas on my 400 mile trip and was going to use e85 on way back but couldn't find it, so put 87 e10 back in. Truck ran good on trip and back no spark knock/ping. When I had mine at the dealer I could smell what smelled like my brakes burning from them trying to put the truck under load. I can't duplicate it. Mine just randomly will do it. I still had some 87 e10 left in tank and put some 93 e10 on top and 4 oz. of marvel mystery oil just to see if it helps clean up anything. I read a old thread on a 2010 4.6l that someone was complaining about the same thing we and you are. It turned out he had a failing fuel pump, I wonder if that is what is happening to yours since you can duplicate it. I had one to fail on a brand new mustang before. Let us know if you find out the issue.

Venuspie

iTrader: (1)

Update: Found a new dealer who definitely hears the spark knock. It is not a engine knock. It is a spark knock that you would get from bad gas or too much timing. Problem is that ecm is not throwing any codes and truck runs ok except for the spark knocking. They replaced the Mass Air sensor and thought it was fixed. It is not. Going back Monday morning to leave it again. Ford is suggesting fuel pressure issue but we will see.

Venuspie

iTrader: (1)

They are thinking it may be the fuel pump. We will see. I just hate I dropped it off on Monday and I watched it set in the same spot not being touched for days. Today I called to check in and was told fuel pump. Maybe it has been sitting while pump on order...who knows. Aggravation!!