Weird sound from valve cover????

[V8slayr]

Both my brother's KA 240 (190,000 mi) and an Altima (KA w/ 165,000 mi) that my other brother is looking to buy sound like they have marbles rolling around in the head. I haven't pulled valve cover personally to investigate but my uncle, a mechanic, has and found nothing obvious. Has anyone else heard this and if so what have you found as the source. Thanks

[s14derrick]

awe the old ka timing chain rattle. the sound you are hearing is the timing chain rattling against the top of the valve cover. its quite common. pull the valve cover and you will see wear marks on the botton of it. either that or if it still has the top timing chain guides remove them. that should help get rid of the noise. if you search you will find multiple threads on this. and also write ups on removing the chain guides. hope that helped

[p0onsta]

Yup, Nissan actually issued a bulletin on this.

The quick fix is to remove the tensioners and clean them, making sure that they rebound and flow freely.

Once that is cleaned, the top guide (which sits too close from factory, and makes noise) can be removed. With a properly working tensioner, the chain has no reason to hit the valve cover.

Same can be done for the bottom tensioner.

FYI, this should be done asap, as if a piece of the guide brakes off and lodges in bad places, nobody will be happy.

ps. also bumped your thread about the safc. plz email me @ [email protected].

Thanks.