My car is a 5.5gen 3.5L. When i start the car the engine rattles almost like a bearing knock. It will do it if i rev it, down shift, in between shifts and when i shut it off. I replaced my main timing chain tensioner hoping it was just the chain getting slack but of course it fixed the problem for about 15min. I was told to just replace all the timing chains and guides but im in college now and cant afford 1500 worth of parts at once. Has anyone know what could be making the rattle?

 

Are you sure it is coming from the engine itself? I had a loose heat shield on one of my precats that rattled anytime I let the car idle, or turn it off.

What type of gas are you running? It could be knocking from using low-grade gas. run a search using the word: knocking, there are plenty of threads out there that can lead you in the right direction. GL

 

no its its some where in the timing cover it sounds like it might be the cam in the front

 

did you ever find a solution? I have the same problem at the moment.

 

i had this problem.....my rear header precat was loose and was shacking inside the header...trust mee ill bet my car on that thats the problem

 

Not sure if this has played a role, but has such a noise ever been tracked down to the Hydrolic Lifters?