Upcoming Head Gasket replacement

[kleake]

Same here, and I do hope that's all it is, but it sure doesn't sound like it. Definitely sounds more like one stuck open instead of not opening enough. I have a hunch that I have a rocker issue of some sort. My worry is valve/piston contact, however I haven't heard anything that sounds like metal to metal.

Called a couple of local shops, none have heard of an issue like this. Just my luck.... I don't see how I could have installed anything incorrect, it's pretty straight forward, but anything is possible.

 

[Lipka101]

Same here, and I do hope that's all it is, but it sure doesn't sound like it. Definitely sounds more like one stuck open instead of not opening enough. I have a hunch that I have a rocker issue of some sort. My worry is valve/piston contact, however I haven't heard anything that sounds like metal to metal.

Called a couple of local shops, none have heard of an issue like this. Just my luck.... I don't see how I could have installed anything incorrect, it's pretty straight forward, but anything is possible.

Pushrods were seated in the rockers correctly? A couple of mine wanted to move out of place as I was torquing the rocker assembly.

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[kleake]

I am pretty sure they were, but that might be a possibility.

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[Wizbangdoodle]

I hate to say it, but you may have to dig back into the motor.
No codes when you crank it?

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[kleake]

I don't mind pulling a valve cover and looking at rockers and push rods, I really hope I don't have to go deeper and pull the cab again. The only code was low fuel pressure, however that was air. After it started trying then no more codes. It hasn't actually started and ran on its own though.

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[kleake]

Well, my suspicions were correct, however i'm not sure why. Pulled the driver side valve cover and checked rockers.

#2 intake, #6 intake, and #8 exhaust are always tight. The question is why? Push rods look correct, rockers look to be positioned right and the ball tip looks right. So either the lifter is stuck in the up position, which isn't likely or the valve tips are too high? How can I check?

Also, I assume all of the bridges are the same with the slotted end going towards the center of the head? This is how they were when I took them off.

If 2, 6, and 8 are the issue on the left side, per the firing order that means #1 is the issue on the right side since they are in sequence. Firing order: 1-2-7-3-4-5-6-8

Next question, is there an easy way to loosen the rockers without pulling injector lines? I'm not really wanting to have to replace the lines just to fix the rockers, but I don't see an easy way to get at the hold down bolts.

Oh, but I did get it to start and run, rough until rpm came up to about 2k and then it seemed to get better, but at idle, definitely rough.

 

[sootie]

The injector lines are technically single use but I wouldn't be afraid to undo them and RE torque later, just make sure you get them tight

 

[6.4f350]

Well, my suspicions were correct, however i'm not sure why. Pulled the driver side valve cover and checked rockers.

#2 intake, #6 intake, and #8 exhaust are always tight. The question is why? Push rods look correct, rockers look to be positioned right and the ball tip looks right. So either the lifter is stuck in the up position, which isn't likely or the valve tips are too high? How can I check?

Also, I assume all of the bridges are the same with the slotted end going towards the center of the head? This is how they were when I took them off.

If 2, 6, and 8 are the issue on the left side, per the firing order that means #1 is the issue on the right side since they are in sequence. Firing order: 1-2-7-3-4-5-6-8

Next question, is there an easy way to loosen the rockers without pulling injector lines? I'm not really wanting to have to replace the lines just to fix the rockers, but I don't see an easy way to get at the hold down bolts.

Oh, but I did get it to start and run, rough until rpm came up to about 2k and then it seemed to get better, but at idle, definitely rough.

That's weird. Lifters don't have an "up" position, they ride on the cam. Fuel lines have crush seals in them, reusing is a bad idea. They're cheap enough it's not worth chancing it.

 

[Wizbangdoodle]

Never, ever reuse the fuel lines. You're just asking for trouble.

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[kleake]

Pulled lines and removed #2 rockers. Only took about a half a turn on the hold down bolts before I could move the rocker. Swapped push rods and bridges from intake to exhaust, inspected and all looks right. Put it back on, same thing....... Thinking valves were not ground to match the head surface, however I am very tempted to try shimming the hold downs with tin foil. lol

 

[kleake]

Backed those 3 cyl off about 1/4-1/2 turn, crank it over and it definitely changed it. Can't tell if it's only 1 or 2 that is still doing it, but that is the issue. #8 I barely just removed the torque, not even loosening the bolt and I was able to move the rocker.

What do you guys think is the source? I'll bet I could put my worn rockers on and it would fix it right up.

 

[Lipka101]

Backed those 3 cyl off about 1/4-1/2 turn, crank it over and it definitely changed it. Can't tell if it's only 1 or 2 that is still doing it, but that is the issue. #8 I barely just removed the torque, not even loosening the bolt and I was able to move the rocker.

What do you guys think is the source? I'll bet I could put my worn rockers on and it would fix it right up.

How much did your machine shop take off the heads? If that was the issue it would be all the cylinders. Not just a few random ones? Lifters didn't fall out the bucket and turn on you did they?

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[kleake]

Remanned heads from Ford, no idea what they did to them. Wish I knew.... If the lifters fell out of the guide, 1. I don't think the closed position would be any different due to the point of impact on the cam, but the ramp would definitely change. Also, I made sure the guide moved under it's hold down so there shouldn't have been any binding. Doing a compression check right now to verify, also testing an old rocker to see the difference.

 

[kleake]

Verified--- #4 and #6 are actually holding 360psi on compression. #2 is at 360 with an old rocker, but at 0 with a new rocker. #8 is at 360 if I just bust off the torque on the bolts, but is at 120 if fully torqued down.

What makes this really weird, if #2 and #8 are the issue on this side, and by the sound of it cranking, all cyl that are missing are in sequence, per firing order (1-2-7-3-4-5-6-8) that would mean that it must be cyl 8, 1, 2, and 7 that are causing the issue. Now,,, the interesting part is that is the front two and the rear two cylinders.... Front valve on #2, rear valve on #8. I don't know about the right side, but it may be the same. Is the head flexing on the ends?

I know, i'm getting pretty scientific about this, but I want to know what the issue really is before I go tearing in any deeper. So far it seems I could either use my old rockers or modify the new ones and be fine. I know that isn't really the best option, but it would work and likely be fine.

 

[Wizbangdoodle]

I know for myself, I'd have to know exactly what the problem is and correct it. It sounds like you are on the right track, but may be over thinking it?

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[kleake]

I know, i'm exactly the same way, I want to know for sure as well, but if it is that the heads were shaved too much, rather than pulling them off, somehow changing rocker clearance would solve the issue. Similar to putting in a shorter pushrod, which I hear is an issue on the 6.0's. They had this issue after shaving the heads and they switched to the 6.4 pushrods which are something like .047 shorter. Effectively that's about what I need. I wonder if the early Job1 trucks had a longer pushrod and they switched to a shorter one at a later date? Hard to say... I'm pulling the right valve cover now to see if my assumptions are correct on which cyl are at fault.

 

[Wizbangdoodle]

So, if I understand you correctly, you bought Ford remans and sent them straight to the machine shop to be prepped? Is it a reputable shop? Any chance they screwed up the machining?

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[kleake]

Yes correct, however all they did was take a file to the ding that UPS put in them since that was small. About 5 or 6 strokes of the file took it off. They then checked them for any warping and called it good. I don't think they did anything beyond that, and definitely didn't resurface them. It is a reputable shop, it's the primary one that all the big diesel shops in the area use, but also the one that refused to find me new heads after saying they would. In this case I don't think they did anything wrong other than maybe verify valve stem height.

 

[6.0 Tech]

If the valves are closed properly with the old rockers, but not with the new ones, it sounds like your rockers may be sticking, or misbuilt. We have had some issues with thenew rockers, mostly coming apart or damaged, but not saying this cant happen. Try swapping one of the new rockers from a good cylinder, and see if it is good on one of the bad cylinders.

 

[kleake]

6.0 Tech, you might be on to something here.

Passenger side, #1 was at 0, loosened it up and I got 370. Just snug, about 20ft/lbs of torque and I got 340.

#3 I got 370 tight, swapped rockers with #1 and now I have 0 even snug, however #1 now has 370 snug and 150 torqued down. Faulty rockers or just minor differences between each one.

I didn't test #5 or #7, figured this is pretty telling of what is going on.

I'll talk to a machine shop and Ford tomorrow. Easiest solution might be to grind a couple thousandths off the bridges and polish them back up. This would prevent future wear and avoids grinding the ball on the rockers or the tops of the valves. I think I would want to do them all so as to not run the lifters completely bottomed out just to work. We'll see what I find out tomorrow.