Engine knocking LDS-456

**cattlerepairman** · 08-16-2019, 09:58

Start, let idle, check manifold at each cylinder, back and forth. You will see the temps rising at each cylinder - unless it is not firing. At those, the manifold will stay noticeably cooler. It will all warm up somewhat but it will not get the same heat as with an operating cylinder.
I would not drive the truck until the issue (or issueS) is/are identified, simply to avoid unnecessary wear and tear on bearings and moving parts.

**Oerthedge21** · 08-16-2019, 10:16

Ok so I'm looking for a cylinder that's cooler than the rest. Will do, I'll report my findings/test results later today

**Jeepsinker** · 08-16-2019, 12:16

You need to change your hydraulic head o-rings and probably the boost pump seal too. Need to stop the fuel in oil contamination first and foremost, then move forward. Running it with fuel in the oil is hard on bearings and cylinders even if not under a load.

**Jeepsinker** · 08-16-2019, 12:17

**Oerthedge21** · 08-16-2019, 12:33

So you think it's coming from the IP then? And I know, I drive it as little as possible but I have to get to work and this truck is all I have right now. I'm in the process of picking up a car this weekend, but until hen sadly I have no choice.

**swbradley1** · 08-16-2019, 13:36

Originally Posted by frank8003

Duh on me, I never even thought about equal length and why but that is why some line are looped around a few times. And the multiple bracket fuel line keepers need to be there. Thanks.
Attachment 773400

You and I both learned something new.

**Jeepsinker** · 08-16-2019, 14:00

Originally Posted by Oerthedge21

So you think it's coming from the IP then? And I know, I drive it as little as possible but I have to get to work and this truck is all I have right now. I'm in the process of picking up a cat this weekend, but until hen sadly I have no choice.

Absolutely coming from the injection pump. Replace the hydraulic head o-rings and the boost pump drive seal and you'll be good to go until something else breaks.

Your knocks could be cylinder liners that are coming apart. That's what happened to my LDS465-1A, which is why I've spent so much effort installing a Cummins.

I surmise that the cause of many windowed blocks is actually the bottom of the liner shattering, catching the piston, and then blowing the rod out the side. Mine didn't window the block because it locked when I was starting it and it hadn't even reached idle speed.

**Oerthedge21** · 08-16-2019, 14:33

I guess I'll order up the IP seals then. I'm gonna do the exhaust manifold test before I leave work today anyway since we have one of those IR thermometers here. Hopefully they come out similair and the HH is what's giving me all the trouble

**Oerthedge21** · 08-16-2019, 16:10

It's quiet from the engine bay, much more noticeable in the cab.

I pulled the fill cap while it was running, engine hot, and the smoke does puff out, if you out your hand over the hole you can feel the gasses pulsing out which I'm pretty sure is a bad sign.

**Jeepsinker** · 08-16-2019, 18:02

Yup. Start looking for an engine or planning a swap. You have damaged pistons and/ or liners. These engines really aren't worth the cost to overhaul anymore for their average lifespan ( 40-50K miles)