6.2 slight engine knock and rough idle.

[dawgs5738]

So I think I’m going to try to rebuild it. Can any one point me in the right direction on what parts to buy?

 

[jdm_sixtwo]

So I think I’m going to try to rebuild it. Can any one point me in the right direction on what parts to buy?

Do you want to stay stock or go for an upgrade? Upgrade id say livernois. If you’re staying stock just find OEM parts on rockauto. That’s what I did for my last rebuild.

 

[Canuck714]

Cant really direct you on what parts you need until you know what failed.
Also, what are your intentions with the truck? Are you keeping it and playing hard or just a daily? That will also determine what direction to go.

The 6.2 platform is pretty stout, it has a couple soft area's that you should address on the rebuild regardless of what you intend to do with the truck. To me the first 3 are a must if you are already tearing it down.

The first is valve control. The stock valve springs are known to fail, replace all of them with PAC or Comp, they make a kit for it.

Pistons are next in line. While they generally are not an issue on a stock 6.2 unless you have a valve spring failure, they are known to crack under pressure. Manley makes a good upgrade piston for the 6.2.

Oil Pump gears are known to crack. Usually this is caused by sudden load/unload situations. Guys that stay in the throttle spinning the tires and getting bad wheel hop are the ones that notice this. Made worse when adding power like a blower... Tons of info on it.

Finally connecting rods. Not known to be a problem unless you have something else go catastrophically wrong. It has happened, but not common to chuck a rod on a N/A 6.2.

There, with that out of the way there are some things to consider if you are going to rebuild your engine. You need to get it tore down to know what failed before even looking up parts. If you had an oil issue you most likely lost the top end as well as other bearings so you will need everything!!!

If that's the case this is what I'd be doing... Send out the block and crank to get hot tanked and inspected. If the heads aren't garbage send them too.
Have the machine shop measure the bores for size and roundness. Once you know what you need for slugs, order up Manley pistons in the size you need. Probably 20 thou over to correct any bore wear etc. That way the machine shop can bore the hole to match the pistons.
Then I would add Manley I-Beam Rods, with King Race bearings or Cleavite, whatever good bearing you trust (i like King)
Hopefully the crank just needs a polish and new bearings, if not you are into a new crank. The stock crank is strong, no need to upgrade here until you are past 1000 hp.
If the heads are good but have 300K on them I would have them machined to make sure they are flat, new valves and seals and put them back together.
If the cams and journals are toast you have other things to consider.

Lots of things to think about... If you have time and some skill its not a hard job to rebuild, just have to know what needs attention. If you are not up to the task, maybe the Schoenfield guy thats close to you needs a call.