Hi all, new member here, I have been lurking here for years and enjoyed many hours of reading some really great posts. I live in Nova Scotia Canada and my Truck, a 2011 extended cab XLT with the 5.0. It is my third F150 in the last 16 years, the first one was a 95xl 4x4 with an indestructable 300 engine, that was my first truck and I was not kind to it but it was a tough sob that could take it. My next one was a 99xl 4x4(kept it for 10 years)4.2 v6, it was rusting terribly, so a new truck was in order. So last January(2012) I decided to go for a new one, there were so many incentives including $2500(recycle your ride) $9250 (2011 5.0 discount not on ecoboost) $1000 for being a Costco member and the dealer gave me an additional discount for buying a left over 2011. It is an xlt 4x4 with a 3:55 rear and it has a nice back up camera which is very slick. I have loved this truck from day one, the ride, power and quiet cabin have been awesome. I currently have 22,000 kms(14,000 miles) on it. Long winded post, finally to some issues, I had to have the rotors re-surfaced last week, that seemed early to have that problem. I also have had a spark knock issue, this has been going on for about 3 months, the truck pings under load on the highway and also at low speeds when lightly pressing the gas pedal. I took it back to the shop and both the mechanic and service manager road tested and heard the spark knock. They hooked it up to an analyzer and it showed no codes. they have no fix for the problem, the only thing I know to do is switch to a higher octane fuel. (I was buying 87) If anyone has an advice on what I should do or if you have had similar issues, then by all means please give me some info.

 

Welcome the FTE.

If it was a fuel supplier issue you could try other suppliers but unfortunately all your fuel for NS (and NL) comes from Imperial Oil. So it doesn't matter where you buy it, it's all the same.

We have the same issue over here on PEI as all our fuel comes from Irving.

Did you try 89? Maybe winter blend? Other than that I can't provide much help.

Sorry
S

 

I should add that the reply from Ford to the dealer mentioned about ethanol content in the gasoline as a possible cause for the spark knock. I was just wondering if an posters stateside have had any spark knock issues with the 5.0 or even the ecoboost. I will also say that for a truck, my fuel mileage has been awesome. I get between 10-12 litres per 100kms on the highway which for a truck is amazing. We also have a car (Nissan Altima) and it sits in the driveway for any road trip and the truck is always used. I love my truck and this is just a minor issue which I hope will go away.

 

I was thinking bad gas too... Even though the fuel may come from the same refinery, some gas stations have actually been known to add some water to the gas in order to "stretch" it. The ethanol in the fuel allows for this to work somewhat. If too much water is added, you will certainly get a knock, as the gas is "diluted" if you will. I'd try a different gas station. The ethanol itself shouldn't cause a knock on a 5.0, as it is a flex fuel motor, and should actually run stronger with more ethanol (though mileage should drop).

 

I am going to buy high octane for the next few weeks to see if it makes any difference.

 

That seems a far stretch but anything's possible. They would have to either add it to the tanker truck or right at the station. All the fuel comes in to PEI on a ocean tanker, pumped to the depot/tanks and from there, tanker trucks load for deliver to the gas stations. All from the same bulk tanks.

 

All the dealer knows how to do is check codes? I'm not even educated on this subject and even I know they should monitor activity on the knock sensors and how much timing is being pulled back.

The dealer can't do much other than throw parts at it. The people that probably know most about this subject are custom tuners. You might be best off talking to a tuner like 5 Star or Livernois Motorsports because they can pinpoint the cause a lot quicker and can do something the dealer cannot -- change the tune. There are other tuners, I'm sure, but I'm not into the Ford racing scene and don't know the players.

Good luck.

 

When I first took my truck in, the service guy said that he felt it was a timing issue and he ran the tests and then corresponded with Ford and when I checked back he made no mention of his initial claim, he just said that Ford told him that it must be bad gas that is causing the problem. I am thinking of calling Ford myself to see what they will tell me.

 

You can call Ford but it will probably be much more effective if instead you can prove the problem exists.

Here is my suggestion how to handle this.... Run the fuel level down and then walk into the dealer and tell them to physically take you to the very same "good" gas pump they use and fill up your truck from that pump while they watch you do it. Make the service rep ride along while you fill up gas. Three reasons:

1. Make them participate with you so they remember with total clarity and believe you.
3. Burn up their time with a menial task. The service rep has better things to do then sit and watch you fill gas. They'll work harder for you after that.
2. The issue becomes so obvious that even a desk jockey 2000 miles away can understand. You'll need that person to understand because it seems the dealer hangs on their every word.

 

I might just do that Qwktrp. I just wonder about the long term damage to my truck if this remains, or if there will be any at all?

 

My understanding is a knock that is audible is pretty severe knock. At minimum, I wouldn't drive hard under that condition. If it ever gets to the point where the knock won't stop then you need to shut down the engine immediately. Severe damage to piston and cylinder valves is possible. And enough heat can be generated to melt metal.

Basically, the fuel mixture is detonating before it should. There are multiple possible causes with fixes ranging from the very simple all the way up to a rebuild of engine short block and cylinder head.

In short, you can't let this go on. It needs to be sorted out. Drive gently in the interim.