Diesel Doc

yep the valve for that rod should have been loose

Txwelder

The valve or the rocker? Im just not sure if I can tell a bent rod without rolling it on a table.

JKM

If you had a bent push rod , the valve clearance (between the rocker tappet , and valve stem) would have been WAY out of adjustment. Without pulling the pushrods out there is really no way to be 100% sure that none are bent.

You can look for a valve adjuster that is turned into the rocker alot more than the others, and start the engine with the valve cover off, watch, listen , and feel for a rocker not moving right.

you could still have a lifter getting chewed up too....

Txwelder

I started the truck with the valve covers off and didnt notice anything out of the ordinary, well, as compared to the rest of the valves, they could all be messed up and I wouldnt know. I looked, listened, felt, smelled and tasted, nothing looked abnormal.

Txwelder

So some months later and I sitll have the same sound coming from the engine. Have made an 1800 mile round trip and got average 18-19 mpg. If I had internal problems such as lifter/valve/piston, would I have gotten that kind of mileage?

smoke_pedal

you'd have problems by now if it was valvetrain related. check your flex plate bolts. I am not joking. I bought a car that a guy thought had a rod knock, and it was just the bolts that hold the flex plate to the torque converter. Since then, I have found a couple of people with the same problem. With the cummins engine's reputation of cracking flex plates, maybe you could look up there with a flashlight and see if you have any cracks on the "spokes" where the hub meets them.

Txwelder

Checked the bolts and all are tight. Removed inspection cover for flexplate and cannot really see far enough up in there to tell if it is cracked.

LanceD

have you tried using a stethescope to find the area where the sound is coming from?

Txwelder

Ive been through quite a bit to find this problem. Stethescope, new overflow valve, valve adjustments, tightened TC bolts (werent loose), replaced all filters, lift pump is less than three years old, replaced belt, replaced exhaust manifold gaskets, inspected manifold for cracks etc, etc, etc, and still nothing.

MadGoat

Check to make sure your valves aren't pulling through the valve retainers. Have you ever free revved it and let off? New spring retainer and keepers may take care of it.

If one it pulled down it'll cause a miss just line a bad injector or scarred injector pump bore.

This is all just from my experience though, so it may or may not help. Thought I'd just the love....

scout98

Did you ever find the problem? I have my truck sitting for a simular knocking sound. kind of looking for that magic fix as well

Jw Jw

Where exactly is it located. We nd gen swap 6 7 467 turbo new head and gasket...head was cracked #6rod bent...
Started last night and I'm knocking must find this cover plate tj check lifters..help

texasprd

It runs nearly the length of the block on the driver's side, held on with six fasteners. It's mostly obscured by the injection pump. It's stamped sheet metal in OE form, and may have a sound-insulating piece on it. You still have the vent tube that sticks down under the truck? That connects to the vent in the tappet cover - follow that vent tube back up and you are at the back of the tappet cover. If you can't do that, google "cummins 6bt tappet cover" and you will get pics of the expensive billet aluminum versions - some of the pics will show them mounted on the engine, so you can see where it is. And, if you go back to the forum level, there is a button on the right to do a search of the entire forum. If you search for "tappet cover" or "lifter cover", you'll get lots of results

oldblues

hi
sounds like std lift pump sound .
mine does it also
turn up the radio , keep drivin !