Ok so here it is I got a 2001 Monte carlo ss 3.8L and it makes a slight clattering or knock when at idle and ONLY when its warm and it does not go up with the rpm it stays constant when it does it but it is intermittent. This noise doesn't occur all the time it hasn't got any worse since i bought it last year . I need your help on this one because its bugging the hell out of me of what can it possibly be. yes I know my spelling sucks ....Help me out here

Replaced parts radiator ,coolant tubes. TPS, IAC, EGR, MAP, CPS, belt and tentioner, Cat, resonator, fuel pump, coolant fans, oil replaced every 3000 miles, seafomed entire engine , bank 1 O2 sensor ,air filter,

 

Hi `Dex,
Sorry about your problem, but a knock could be anything internal (?)

My guess could be a weak or bad oil pump that is going bad & not providing enough oil to lubricate your internal parts at idle ?

Please check back & see what our expert member's post on your problem (I'm not a expert 4-Sure)..

Good Luck on your knock problem!

Oh, how many miles on your S.S. ?

 

Its got 224,576 thanks for the response