Hi, I purchased a 2011 F-150 with the 5 Liter engine a few weeks ago on an auction from a retired farmer. It has 13000 miles on it.

Yesterday while pulling my 4500 pound Travel Trailer the engine made a noise under acceleration that I believe was a detonation noise. ( or perhaps more accurately called pinging ) I was surprised ! We used to have the problem back in the old days of distributors and carburetors but, I haven't heard this in years.

I was accelerating fairly hard. Not flooring it but, pulling away at a good speed when this happened. It did it a couple of times. This morning on the trip home it did not seem to be doing it.

The gasoline I am using is made by Cenex . I get the gas for free from my employer.

Has anyone ever had this problem? If so how do I solve it ?

Thank you for any responses you can give.

Have a nice Day
Caveman Charlie