Hey when ever i gove my 99 150 gas it sounds like a rattle happens but then goes away once i get to 1300rpm... but when i decelrate u can hear it again... is it maybe my heat shield a loose exhaust...any ideas or suggestions

 

yea it sounds like somethings loose. just slide under the truck and find what it is.

 

yea check the exhaust shields or for a rock behind one of the shields

 

is it coming from inside the engine or outside

 

its coming from out side the engine... i think i might of found it... one of my cadilac converters is loose... lookslike my clamps all usted out.... i took the two that broke off and it stopped for a bit and the started... thats the only other thing losse under it... and i take it, that its not good if u can lift and lower your exhaust system right... i can litearly raise it up to my chasis and it will stay or lower it...