I have a knock at idle, and at 1500rpm it turns to a clatter,only after it has warmed up from 20 f. But when its cold no noise at all just a little when I rev it. I have a post under engines , check out all my ideas on potencial causes of these noises. I read a post way back in 2000 that said it could be clutch plates and a lack of pressure. This problem came on suddenly according to the previous owner and he thought he had a ruined engine. I still think it could be something simple. Am I barking up wrong tree , would it be worthit to drop trans pan and change fluid. Another simptom this truck has,is that in drive and warmed up and holding it with brake pedal, I can rev it up and there is no knocking. Someone knows the answer out there . :Thanks Bob

 

lol your going through exactly what i went through along with my dad. what it is, when your motor is really cold your hearing your heads abng a lil bit, i had a 91 bronco that did it, my dads 97 expedition did it, along with my buddies 02 f150. its all about it being really cold outside. think about it, when it gets cold, molecules move slower (oil), so when you start your truck and it knocks, its just becuase 20 degree oil does not move all that fast. man it just happens, nothin really to do with the e40d and its not necessarily bad