01 with a knocking noise

I am looking to buy a 2001 Intrepid with 75,000 miles on it.The problem is it has a knocking noise.The car runs very smooth but it knocks.It sounds almost like it's coming from under the valve cover though. But it's hard to pinpoint without having it on a lift and really listening to it from underneith..

But from my experience normally a bearing knock will cause the engine to shake slightly,This one is smooth as glass. It fires right up and idles perfect.. I pulled each coil pack plug off while it was running one at a time and the noise didn't change at all it just caused the car to miss till i plugged it back in.So that kind of rules out a rod bearing,if it was a rod bearing it would of quietened down when i pulled the wire off,But it still could be a main bearing..

The girl that has the car said it started the noise all at once.The car is in real good shape and i can get the car for 1000 bucks or so..Even if i have to rebuild the 2.7 i should be less then 2500 or so.."I'm a mechanic and would do it myself"

I just wondered if others that had engine failures had the same symtoms or not..I have read all about the sludge and the issues with the 2.7.Just haven't seen any posts that actually said the symtoms when it did finally let go..

Thanks
Steve

Sounds like it is coming from the bottom end,a rod knock.If you buy the car there is a cheaper way, a 2.7 to 3.2 conversion.All you need is the 3.2l engine with a/c compressor,throttle cable,heater hoses,3.2 L computer,power steering pump,a/c compressor,a/c lines,front of exhaust and radatior intact with a/c condensor.The 3.2L will fit with no problem.I did that to my father's 1999 Chrysler Concorde which he sold later and it had more power than when it had a blown up 2.7L engine.