I hate to bring it up again (timing chain).

[NIK90s13]

Yes it can and will strech(both chains) But it really shouldn't jump timing from streching, it should break instead of jump. Pull the valve cover inspect the round parts of the chain links that are in the middle inbetween the sides of the chains. (That is my best discription) Look for cracks, if the chains are showing cracks then replace it.If that is ok, then pull the guides and run it and see if it rattels.

[hipro]

First step in my opinion... pull the valve/rocker cover and either remove or confirm the upper guide is gone. If the upper guide is still in place, definitely remove it before it fails and causes catastrophic damage. Once you remove it, replace the valve/rocker cover gasket and put it back in place. Crank it up and hope the rattle is gone.

If it has already been removed, I would then begin the next step of pulling the timing chain cover and looking deeper into the issue. Be warned that replacing the timing chains is a big undertaking... I had rather swap an engine than replace the timing chains, especially with the engine in the chassis. There are lots of items to be removed and the real problem is dealing with the oil pan while in the chassis. Because of the oil pump pickup, you have to substantially raise the engine or drop the front crossmember to get adequate clearance. It probably is easier just to pull the engine, put in on a stand, and do all major maintenance while it is out. Good luck. Mike B. www.hiprollc.com