Push Rods

[peacemaker4500]

I have some bent pushrods in my 97 7.3L .

Replaced 2 of them a few months ago. Had 3 different one bend this time, no load coasting is 5th gear on flat to slightly downhill grade of a road, no trailer, foot not on pedal... I dont understand why they bent.

Maybe since they are not the same rods as last time, they broke/bent becuase they were 'stressed' at the same time as the fist ones that broke/bent. ??


So.. I bought all new push rods in install, while I had everthing taken apart this time. (only around $2.00 a piece..)

I replaced all of them on the passengerside, and started the truck with the valve cover off, so that I could watch them operate. I have one cylinder that is not working.... !!!!! The pushrods and the rocker arms do not move on the intake and exhaust of one cylinder. All they others are fine. On this particular cylinder the push rods were broken/bent.

What is the problem here?

Thanks.

[Jon5212]

Sounds like you broke a lifter or very unlikely you lost a lobe on the camshaft. But more than likely your lifter is shot. Although I'm not familiar with diesel engines, their principals are almost the same as gasoline.

[elibenson]

Broken lifters? I have heard of them splitting down center, or crushing. Perhaps they are were jammed after they broke.

What I would do is start the truck, and put your finger directly on the end of the push rod and feel it to see if it is moving at all. If it is moving a tiny bit, it might be the hydraulic part that has collapsed. This could be an oil pressure problem (like a clogged gallery) or possibly from a broken lifter.

good luck

[peacemaker4500]

I was hoping it was a lifter issue.. i couldnt understand how it the cam could be damaged. I appreciate the feed back guys. I will take a look at the truck tomorrow and see if I can feel any movement at all.

Is anyone familiar with the difficulty of a lifter replacement? I'm not afraid to dig into it.. just wondering if there is any special items that need addressed?

Thanks.

[SCUFFY828]

are you sure the pushrod is on the lifter , easy to get it off to the side

[peacemaker4500]

I am pretty sure.. I will check that out as well, and post back

[Marty]

As scuffy said. Then again it's ironic you would have screwed up neighboring pushrods. Also when you installed them did you have the piston at BDC? Did you wiggle the rocker arm to make sure there was play (lifter relaxed) before moving on or starting the engine? If not you could damage a lifter, bend another pushrod or even a valve.

[peacemaker4500]

i put my finger on it, and they dont really seem to be moving at all, one side gave me a small vibration, as if there was a really small movement, double checked, and both seem to be in their seat.

[Marty]

Have someone turn the motor over by hand, err well the crank nut. Watch the rods very closely. I wouldn't run it if they truely aren't moving.

[LBZinthehizhood]

I have a 01 7.3 and the pushrod was laying loose on the #8 cylinder Im pretty sure the lifter collapsed although I havent turned it over to make sure. Can I pull the lifter out with the head still on? Also the pushrod is as strait as can be