803 Bogs Down and dies at 85% Load

[justacitizen]

If I were to bet on when.. I bet it was an error upon assembly. The scenario would be that the valves were tightened down and the unit started without giving the minimum wait time for the lifters to bleed down.

OR.. You have a bad lifter.

or an upside down lifter?

 

[USAMilRet]

i see cracks in one end. i wouldn't reuse it. i would use it to see if the lifter is locked? can you remove the lifter without removing the head? with a magnet on a stick?

No. Can't be done as it will not fit into the valve push rod tube. I am not even sure I can test the lifter. It looks hydraulic to me but I can not push down on the internal spring to pump the lifter. Maybe I am just not putting enough umph onto the rod.

 

[jbayer]

I would want to pull the head after seeing that, just to check on things. Did the valve hit the piston at some point maybe? Unless you have access to a borescope, and can borescope it.

 

[justacitizen]

If I were to bet on when.. I bet it was an error upon assembly. The scenario would be that the valves were tightened down and the unit started without giving the minimum wait time for the lifters to bleed down.

OR.. You have a bad lifter.

or an upside down lifter? better get a good light and look down that hole

 

[USAMilRet]

or an upside down lifter?

Not upside down. I can visualize it down the tube and can see the top clearly.

 

[DieselAddict]

or an upside down lifter?

Wow. That would be a first but lets hope not. You'll be replacing a cam if they did that. I can't imagine that wouldn't stand out since the rocker arm will be jacked up a lot higher than the rest.

 

[USAMilRet]

I would want to pull the head after seeing that, just to check on things. Did the valve hit the piston at some point maybe? Unless you have access to a borescope, and canborescope it.

I do not know but I do not think so. The break looks like metal fatigue to me.

I am still not convinced that I do not need to pull the head.

 

[justacitizen]

take one of the other rocker arms off and compare the known working lifter to the suspect lifter. try pushing and pumping both to see if they are similar.

 

[DieselAddict]

Pulling the head will remove doubt. If it were in my shop I'd have the head off of it right now. But thats me.

 

[justacitizen]

Not upside down. I can visualize it down the tube and can see the top clearly.

that is good news.

 

[justacitizen]

No. Can't be done as it will not fit into the valve push rod tube. I am not even sure I can test the lifter. It looks hydraulic to me but I can not push down on the internal spring to pump the lifter. Maybe I am just not putting enough umph onto the rod.

if you can't pump the lifter and it compares to the others that you can pump it would be likely that you may have a collapsed lifter.

 

[USAMilRet]

You know I swore that I would never do a half job again on engines some time ago. I recently made and exception on my 95 Ford F150 and did the lower bearings while the tranny was out but the engine still in the vehicle. But I was told less than a year before that, that the upper was in great shape by a mechanic that has been working on my cars for some time now.

Here I am faced with the fact that the engine was rebuilt recently, torn down, built again, then passed on to me Hard to believe that Scot would have not seen that between the builds as there were no gaskets on the valve covers. If it was not overlooked, then this is recent and got to tell you that yesterday after I worked on it some, it sounded different from days past. Almost like it was skipping, as we would say when the ole spark plug failed, in gas engines.

So if this is recent, then the problem is still going to exist. I am beginning to think that it would be unwise to stop at this point as I need parts and they are going to take a couple of days to get here so I have the time to continue down the tear down road. I have to empty the radiator anyways because I have flush in it right now and it is time to cycle it out.

Finding this broken rocker arm may mean that there are metal chips in my enigne oil right now and that my new break in oil is not trashed along with the brand new oil filter. This means that the crankcase cover is going to have to come off so that I can get everything out of the sump. At the same time, it would give me an opportunity to readjust my oil pressure relief valve up a couple more psi. I do not think running at 22 -23 psi when warm is adequate. Maybe up it to 35 psi. It is showing about 50 psi when cold but that only last about 3 minutes.

 

[USAMilRet]

if you can't pump the lifter and it compares to the others that you can pump it would be likely that you may have a collapsed lifter.

True, but to find that out, I have to remove another couple of valve rocker arms. Another reason to just keep going.....

 

[USAMilRet]

Pulling the head will remove doubt. If it were in my shop I'd have the head off of it right now. But thats me.

I agree. But I do not have much of a shop and I do not have all the tools as indicated in the TMs. I have rebuilt gas engines before but never a diesel although it does appear to be almost identical save the ignition and governor.

 

[jamawieb]

I agree. But I do not have much of a shop and I do not have all the tools as indicated in the TMs. I have rebuilt gas engines before but never a diesel although it does appear to be almost identical save the ignition and governor.

If you have rebuilt any motor, then you can do these. The hardest part about the head is getting the push rod tubes and head gasket aligned while reinstalling the head. It's really straight forward but the head is heavy trying to do it alone. Also it's easier in my opinion to pull and reinstall the heads with the intake and exhaust manifold installed. It gives you something to hold on to. The only trick is, to torque the rocker arm nuts and then wait 30-45 minutes and then re-torque again. That gives time for the lifters to bleed down.

 

[justacitizen]

sorry i need to repost this.

 

[USAMilRet]

Some pictures of what I did today after deciding to remove the head. Glad I did. Apparently intake valve 3 hit the piston. It just scuffed the piston top (not really anything) as you will see in the pictures. Both the piston and valve seem to be OK. No indicatikons of any abnormal wear in the lifters. Things cleaned up well and the pistons were not sloppy at all, rather they were rather tight. Got some pictures of hopefully the cross hatch on the piston sleeves as well as pictures of the rings doing their job once the engine was rotated by hand.

 

[USAMilRet]

 

[USAMilRet]

 

[USAMilRet]

This is going to be my new avatar....