Its a 95 mustang 3.8l automatic. It knocks at idle when hot and gets louder at around 2k rpm. But if I put the brake on and bring it to around 2k there seems to be no knocking. I also dont hear knocking when driving unless its changing gears at a higher rpm. I started it up this morning and it doesnt seem to knock when its cold. I also went through and unplugged each spark plug wire and I got to cylinder 6 and the noise got louder. Im lost. I dont have the time nor money to take the engine apart. Its a Dailey driver with 120k on it. All original from the factory except for, altenator, cooling fan, Serpentine belt, tensioner pulley, a screamin demon distributor, low resistance wire set. X2 platinum spark plugs, head gasket, engine oil and oil filter. Radiator fluid, power steering, brake fluid and air filter. Everything is stock as far as I know.