feroxjb

So after pulling the timing chain cover and replacing the timing set and the oil pump... my ticking eventually turned into knocking.

As I checked my lifters.. the lifters on my #4 cylinder and they were stiff [all the others were spongy.. it's been sitting for about a week. Spongy = good .. Stiff = bad]... I pulled the plugs and checked my pistons for movement (knock)...

Low and behold.....

https://youtu.be/kC4fJSn-S0c

Jnorman831

A stiff lifter doesn't necessarily mean it's bad. It could be that they are just pumped up all the way and need to be bled back down. Also the stock rods are break away rods and unserviceable. We had a customer come in with the same issue you had, we got him non break away rods but he would have to clearance the block for the rear two rods. So he only bought 4 new rods and ran two of his original rods that were still good. He declined to balance his rotating assembly but that's on him. Moral of the story just buy stock rods.

greynolds08

I have a 2008 JKU and I also had the engine knock. So I took it back to the dealership and they found the knock was coming from the Crankshaft Bearings. So the way I understood it was the crankshft had slack in it and hitting the inside of the motor making the knocking noise. So they replaced the engine in mine and this took place about 3 weeks ago. Just something to keep in mind

ronjenx

Breakaway rods? Is that the same as cracked cap rods?

Unserviceable? What do you mean by that?

feroxjb

They rods themselves are called powdered metal rod caps... they don't have a seam where the bolts connect two halves. They're solid. You basically back the bolts out on it, and tap them, and they will literally separate. Not kidding. Freaked me out. They CAN be reused from what I've read, but the break is not smooth and the cap can only be used on the rod that they came with. (obviously)

I'm assuming he means unservicable meaning that you cannot grind the mating surfaces down and smooth them out.

I believe Cracked Cap Rods are synonymous with powder metal rod caps.

While it seems kind of weird.. the metal doesn't crumble or anything.

feroxjb

Same premise with the connecting rods on the pistons. If you watch the video.. you can actually hear the clunk/knock sound when I push down on the piston.

https://youtu.be/kC4fJSn-S0c

ronjenx

Yes, they can be reused, with new shells in them. That's why I was wondering what he meant by "unserviceable".
The 3.8 can come from the factory with regular forged rods/caps, cracked rods/caps, or any combination of the two.

Jnorman831

Yes same thing. They are unserviceable in the sense that if you spin a rod bearing you can not resize the rod like a normal rod. The breakaway or cracked cap rods are great rods so long as you never have any issues with them.

Jnorman831

I never said they can't be reused I said you can't service them. You can't recondition them.