Dan s

Can u have a rod knocking and still hold 40 psi of oil pressure at idle. I have had a pronounced knock ever since I put the new rebuilt injection pump. A mechanic buddy of mine says I'm paranoid

bigragu

Don't fall for the paranoid thing, Dan. It's your truck, you hear the cummins sounds everyday. If something catches your ear, look into it.
I'm no pump expert, as I've only removed and re installed mine once. I followed all the procedures, and realigned everything, and it still isn't right. Not going to get into all the details of my pump troubles, but it sounds like maybe yours got over advanced a bit? Reading on pump timing tweaks from old treads on here, folks that advanced their timing by rotating the pump towards the head, have asked about knocking noises.
Your pump flange has a mark, that was scratched on by the factory when they installed the pump. It should be lined up with another mark on the back of the timing case, where the pump mounts to. Those marks should be directly in line with each other.
Depending on how clean your engine bay is, you may have to wipe down that area really well to see those marks.

You also may just need to adjust your valves. When was the last time the valves were adjusted?

Dan s

I did the valves when I did the new springs. It runs very good. It has a slight miss when it's cold but it clears up after about 60 seconds and is smooth. I think that is an injector. It runs 50 psi of oil pressure when driving done the road. And 30 to 40 at idle.

bigredbrick

I'd say not a rod knock. I have a cherokee I shouldn't have bought that developed a knock after doing a bunch of work on it. I said "to heck with it, drive it". 90,000 miles later it's still running strong and still knocking. With a rod knock you should lose oil pressure.

Dan s

Wish I could post a video. Anyone know how

Angry Johnny

When do you hear the knock? Just at idle, under load, deacceleration, cold or hot or all the time. Can you duplicate it sitting still? If so crack the injector lines one at a time. If it's a rod bearing the noise should lessen when that particular cylinder isn't firing.

If you can't isolate it to one or two cylinders then it's probably not a rod.

BTW I've heard rods knocking in a diesel and it is loud, really pronounced.

Dan s

Thanks. I'll try the injector thing later today. It's all the time. U don't hear it as loud at highway speeds but it there

mknittle

flex plate maybe? I have had them make noises that sounded like something really bad was happening.

Dan s

I don't think so mark. It's in time with the fireing of the motor. Rpms go up it goes with it. I'm about to pull it in the garage and try the injectors. Like I said. I didn't notice it till I put the injection pump on. I'm hoping it is just the way the new pump sounds.

mknittle

If you don't have a mechanic's stethoscope try a piece of hose. maybe you can narrow it down a little

patdaly

A bad Injector can sound suspiciously like a rod knock as well. If it were a rod knock in a diesel, it won't knock for very long............... Don't let it run long with a bad Injector either, that knocking sound is beating the heck outta the engine.

Did you do any Injector work while the pump was out?

bigragu

Any chance the wrong lines got hooked up to the injectors? Got crossed over somehow? What would that do?

Dan s

I would think u would have to bend them pretty hard to make that work. I haven't tried to crack the injectors yet. Gonna try to do it today. Got a buddy that is pretty good with diesels. Gonna let home help. When I get more info I'll post it up. And I still haven't figure out how to post a vid

bigragu

No, not at the connection to the actual injector, at the left side of the head, but at the backside of the VE pump. The lines going to the injector line inlets have a specific order of where they connect to.

Dan s

I got it. Number one injector it leaking past the o ring. Gonna call city diesel Monday. Guess I'll just have all six gone through.