KNOCKING AT START UP

[KMBARROW]

When I first start my 350 griz 4x4 it knocks a little. Not much just enough that it bothers me. It goes away after a few seconds. My 250 does not do this. Is this a problemo?

 

[grizztracks]

Any knock is bad. It sounds like something worn just enough to cause a knock and when the oil pressure increases it quites. If you haven’t had the valve lash adjusted yet you may want to check there first. Normally the intake valves tighten up rather than loosen but maybe you have one that backed off a little. If it has more of a deeper knock rather than a rattle or tapping I would lean more toward the wrist pin. I'd also change the oil and filter and check them for metal shavings. It’s tough to diagnose the problem without actually hearing it but a good mechanic should be able to help you.

 

[maim]

sounds like a collapsed piston skirt to me. but a top end set is not a bad idea.