Alright, My 2.8l V6 engine will kock at idle this knock sounds like a rock in a can shakeing, It only does this when the car is cold and it will stop making the knock at around 200 degrees. The idle is set at the first line after the 500 rpm mark. (around 650ish) What would be the cause of this knock? Now i do know that if i advance the idle to around 1000 rpm, the knock will stop. This really gets me fustrated.

 

I was told that it is not uncommon for engines to knock when they are cold due to oil draining down into the pan and not lubricating everything 100% on start up. Apparantly most of the commercials are correct saying that start up is the hardest time for a car's engine due to the lack of oil on the moving parts up top.

If after it warms up there isn't an issue with it knocking, im not sure if you should be too concerned.

If you can, hook it up to an ALDL computer and record your cold start up and see what the knock counter reads at. If the knock counter isn't reporting very many knocks on start up then it may be something other than pistons knocking.

 

Ive heard the same thing, however if the idel is up at around 1k parked (yes i know its 2 high) the car will not knock.