My ford f150 2006 truck drives great unless going uphill. It makes a rattling or pinging sound with uphill climb. Does anyone know what it could be?

 

Have you looked under the truck to see if there is anything loose? The pining, if coming from the engine; is a lean condition can happen under engine load. Try a higher octane fuel and see if that changes anything.

 

i have looked under the truck,nothing is loose, it sounds like it is coming from under the truck, not from under hood. sounds kinda like loose bearing noise when going uphill.

 

Sounds like it might be 'pinging' under load. Try a tank of higher octane gas and see if that makes a difference.

When was the last tune-up?

 

i added "tune up in bottle" with a full tank of gas, if that doesn't work, then i will try a high octane gas. thanks