Hello
I have an 08 with the 6.4L. I have a knock that nobody can find. It has been doing it for about 15,000 miles. The engine has 200,000 on it now. It is the #8. Engine runs like a top, nice and smooth. All drivers side injectors are new, heads have been off, new lifters and rockers installed. I have no codes. The #8 does have low contribution but not low enough to toss a code. I am getting very tires of the noise and I believe it is getting worse, but it does sometimes almost go away. Very frustrated. Any ideas??
Thanks

 

Does the knock speed up with rpms?

 

Yes, gets quieter with rpm though

 

When let off going down the road at about 55 or 60 can you here it ?

 

Have you not checked the cam or crank shaft bearings?

 

No, it sounds normal when u let off?

Cam bearings are good. Noise is defiantly top end.

 

And you checked all your injectors? Maybe a rocker arm.

 

New injectors and new rockers and new lifters as stated in the beggining. The noise can be heard with a stethascope right at number 8 cylinder at the exhaust manifold.

 

Yea I seen that but didnt know how long ago it was replaced, mileage wise. Them rockers are kind of weak.