ciscohusker

Just bought a 94 that was wrecked in the rear and has been sitting for some time (not sure how long) and it took awhile to get it started fuel system was empty had to reprime. We never got it to run right so I pulled the valve covers off and #6 had a very bent intake push rod I had to use vice grips to work it out. I know the guy I bought it from tried to put some air pressure in the tank to prime the system could that have forced fuel into the cylinder causing it to hydraulic? What else could have caused this?

Ridiculous

the only thing i know of and have experienced is...the engine being out of time, or if the rod broke and the piston slammed into the valve causing it to bend. and you got yourself a good theory there but i doubt it. i would think it'd have to be a whole lot of pressure in order to do that, not to metion how long he would've had to hold pressure on it.

rattlerbob5.9

It could have gotten bent from the engine being reved to high of RPM and floating the valves and hitting the pistons. If you replace the pushrod and the engine does not run right i would suspect a bent or broken valve in that cylinder.

TheBigNasty

Max pressure of an air compressor is what, 180-190 psi? Not nearly enough to pop the injectors, thus no fuel in cylinder.

Ridiculous

hmm, that's something i did not think of, my money is on this one

and that is exactly what i thought, the injector pops at like what, 3000 PSI!!!

ciscohusker

After I posted that I was thinking the same thing. Had it happen on my alcohol injected 460 last year and bent one but that was because those nozzles are free flow not pop off. I will be tearing the head off today to get a better look at what happened.

blackdiesel

i bent one from the rocker arm being too tight...

dieseldork

mcan you explain what a bent push rod looks like ? i had my valve cover off the other day to put on different injectors and i noticed one of the nuts on top of the rocker looked crooked like maybe it was bent . is this what it lookes like ?my truck runs ok and last if it is bent how do you change it and where can you get a new one to replace it with.

Crimedog

You can check for a bent pushrod by taking them out and comparing them with a true straight edge, or rolling them on a flat surface to see if they are true.

TheBigNasty

Most say to roll on glass.

Smkndzl

5.9 are known for bending push rod when they have to much idle time and cold weather.

ciscohusker

Thanks for the replies it does look like the one that was bent had less threads showing on the adjustment bolt on the rocker so it may have been out of adjustment slightly. The other thing we were thinking about is when the truck was wrecked the tranny locked up which would have stalled the motor this jolt could have been part of the culpreit. But after pulling the head I see that I have some other issues with the pistons some one was running the wrong injectors in this truck I will start another post on it.

dieseldork

ok so what all is involved in pulling the push rod out and putting a new one in ?also where can i go to get one for a replacement?

ciscohusker

Pull the valve cover off unbolt the rocker arm pedestal and pull the push rod out. You should be able to get a push rod directly from a cummins dealer. Not sure on the cost haven't called them yet. Here is a pic of a bent one.

dieseldork

htanks for the info .now could the rod be bent and the engine still run ok because my truck seems to run ok .