I have a 01 chevy 2500 hd with A 6.O when you accelerate hard it knocks kinda loud i have also noticed recently when you shut it off sometimes for 10 to 15 seconds steam slowly comes from both tailpipes what do you think it could be i have changed the plugs and wires last week could it be the head gaskets its not running hot at all and it has good oil pressure

 

any help at all

 

come on no one can tell me anything.

 

More info needed.

 

like what type of info pretty much gave you everything

 

Whats the coolent level, any coolent in the oil, is it running hot, has it ever overheated, what is the outside air temp, anything changed when it started doing this, is it steam, or white smoke, is there any water comming out of the tail pipe?

 

coolant is fine and nothing else has changed and temp in the 70s and like i said i dont know if its smoke or steam

 

Does it run ok? Any check engine light?

 

my 95 1500 does the same thing and it is white smoke but it's not a coolant problem, i know that because i redid the entire cooling system along with head gaskets. i'm stuck also

 

if you have white smoke something is burning that shouldn't be more than likely coolant

as for the original poster its hard to say without being there to hear and play with it....is it rpm responsive?? internal engine or external knock?