my 2010 f150 with 4.6l 3v, 64,000 miles. Before winter I noticed a pinging sound like low octane gas, and a exhaust leak sound from engine. Happens cold and warm. I put in 93 octane gas and it sort of went away. I have not taken to dealer yet. My extended warranty is set to expire at 75,000 miles. I was told by my friend, there is carbon build up on the valves. Which is causing the problems. Just wondering if anybody has the same problem and the outcome. I did put in 2 cans of seafoam this week, with a 3/4 full tank. Have noticed very slight improvement.

 

Seafoam doesn't work well in fuel injected engines, and can damage the cats. The addidive that does work and is recommended by Ford is Techron.

I would change the spark plugs, fix the exhaust leak, and get a Motorvac or BG job done.

 

Another friend recommended a BG job also. Some additive you add to oil. Run engine for 30 min, then change oil and filter. I dont have the name of stuff, Will post tomorrow. Also have a front left axle seal bad. And possible oil pan seal going bad again.

 

I don't think you need an oil additive.