Conclusive info on 4D56 head onto 4D55 block info?

[gard]

Alright. So I have read all of the threads and there is good speculation and information but nothing confirming anyone had solved their problem and are running and kicking ass. Here is a run down of my last 4-6 months dealing with this thing.

1. Truck ran and started awesome for me besides some minor tweaks here and there for the first six months but had an intermittent heat issue particularly when it was under a load. The gauge needle would reach an eighth of an inch below the top warning line.(white line not the red). I replaced these things.
A. Water pump.
B. Radiator hoses
C. Thermostat (went from 195 degrees to a 170 degrees)
D. Radiator cap (twice)
E. Reservoir hose and cap
F. Flushed the bejeesus out of the radiator every time I emptied it to replace something and a few times just for that.

2. After these measures the issue finally presented itself in full going up a hill after driving it for about an hour. While going up the hill the needle reached the top white warning line and I had to pull over after coasting the hill. The reservoir was spewing out air and coolant. Head breach. After reading the forum and from what I had seen on the one in the salvage, the head cracking isn’t uncommon, so I began my plans to replace the head.

3. In the process of preparing for the head swap I decided to have the radiator serviced and rodded, and had the turbo, injectors, and injection pump rebuilt.

4. I had a hard time finding a protruding valve head and the one I did find was sent to me with a stuck camshaft, so I decided to try the 4d56 head swap to flush valve. From reading on the forum it appeared others had done this and it had worked fine. The problem is that the threads usually end in advice given and the user with the error never gives conclusive evidence of the project turning out great for them. My assumption was that this meant they were rolling down the road, if they weren’t they would have been back for more advice. So I went for it.

5. I found out during the head swap my head seemed to be fine, but my issue was a misprinted gasket. The metal between pistons to seal the water channel was on the wrong side of the gasket, and it only goes on one way. That being said, my camshaft was junk, and I had mix matched caps from two engines. I still wanted to go with new stuff.

6. These are all the things that have changed or been replaced during this process.
A. Rebuilt Turbo. They used a TD-05 cartridge in place of the TC-05 cartridge because of part availability and to be easier to repair in the future.
B. Had radiator serviced and rodded.
C. Injectors rebuilt.
D. Injection pump rebuilt. (They replaced what needed it, really only the lift side appeared damage during operation, it was assisted by a 5-6psi 30gph electric inline pump)
E. MLS head gasket.
F. 4D56 flush valve head.
G. New oil and fuel filters (the water separator under the hood, and one I had before the electric pump, at this point with no electric pump and just the filter.
H. Flex a lite engine driven fan.

7. I had some issues getting it bled and started the first time, my primer handle doesn’t function, so I put the electric pump in the chain and bled it through the screw on top of the water separator and then to the timing plug on the injection pump. I had left injection lines cracked and spun the key a few minutes until diesel was spitting out of them, tightened them down, spinning the key between. Still not wanting to give it to me, so I used a squirt or two of ether. Started up rough, lots of white smoke, but eventually calmed down and sounded great. From then on it would start, albeit it rough, lots white smoke out of the exhaust, and lots of working the accelerator, then calm down.

8. During this I bullseyed an ear plug down an oil drain tube. Had to remove the pan and retrieve it. Wasn’t going to let that destroy my engine, and wasn’t going to be able to sleep knowing it was in there. Found it. Got the pan back on and took the opportunity to replace the steering components and the rubber on the stabilizer bar. Aggravating, but got something I needed to do done in the process.

9. Drove it the first time around the block and to the alignment shop. Cold start always sucks, lots of accelerator pedal to keep it going at first and high volumes of white remained. When warm, would start repeatedly on half key turn, right to 750 rpms idle and sounding great. In between warm and cold, the truck refuses to start. Glow plugs decide it is too warm to need their help, yet not warm enough to give me the half key turn start. If you unplug the temp sensor, glow plugs initiate and it fires right up, but rough and shitty as usual.

10. With the truck aligned, test driving truly began. Sometimes the thing would take off awesomely, and drive that way for 10-30 miles, then get incredibly bogged down and put out a lot of black smoke. More than I remembered it doing before, or what seems normal for it.

11. I found some leaking diesel around injector 1 at the return rail. Considering this and my compounded issues, I took these steps.
A. New return leaf washers.
B. Extra couple foot lbs torque on the injectors.
C. Replaced all fuel lines under the hood.
D. Put Teflon on the threads of the primer handle.
E. Adjusted down the throttle screw and the total fuel screw up until I was back at the idle I wanted. This time closer to 900 than 750 rpms.
12. I bleed the system of air again, and this time I leave the electric pump in line. Starts like crap, but smooths out. I drive it. Intermittent power loss. Will drive like a dream with more power than it has ever had, and then go limp and act completely starved.
A. Replace the fuel tank.
B. Warranty out the electric pump for one with 7-14psi 35.5 gph.
C. Another new filter before the electric pump.
13. Found out the tank had been coated with something on the bottom that looked like white paint. I assume some sort of rust treatment. Flakes a big as dimes of it floating around. Worth mentioning now, I had seen these flakes in the back filter (it’s clear) and in the plug for the water separator filter. Thinking I had my smoking gun, I start it, I drive it, same results. Lost at this point, I call in help from my mentor and diesel guru to come in person.

14. We check over some things, make sure the system is bled. We try some things.
A. Swapped the fuel cutoff solenoid with the one on the other pump. It is activating better.
B. Remove part of the exhaust and the muffler, inspect with flashlight, and test drive.
15. With the muffler off, there is an obvious noise when the power loss occurs, likely it is misfiring, but intermittent. I let the more knowledgeable and skilled mechanic load up the truck and take it with him. He tries these things.
A. Found the set screw missing and the screw backed all the way off on the 8th rocker arm. Replaced it. Poked around the head to find it, hopefully the drain pain. Never had any noise as if something was rattling and everything still looks cherry.
B. Had my spare injectors tested, they function great, so he swaps them. Finds the current injectors soaked and dripping of diesel. As of last night, we thought it fixed it, drove it around never made the noise, never lost power. He waits till morning and tries a cold start. Still sucky.
C. Trouble shoots the glow plug system and finds that the 6v relay is completely toasted not activating. The wires appear to be getting super hot going into it. He will be wiring a manual set up tomorrow.
D. Ran a compression test. 1-2-4 read 350psi, 3 reads 325 psi. That is in the pocket of what I want? Not cool 3 isn’t the same, but doesn’t seem likely to be the problem?
16. Next few days he will have the injectors he took out tested. Will wire manual control for the glow plugs. After double checking all the timing marks and the injection timing for the 100th time, remove the pump and take it back to the guy with the injectors and have the system ran on a table.


Any thoughts here? Anyone running a 4D55 block to flush valve 4d56 head with no problems? I feel like we should lock that down definitively and not speculatively. Maybe I missed something somewhere but all the threads on the subject tend to trail off and end before reaching no “maybes” answer. I’m going insane and honestly running out of things to check or replace it feels like. But I am also way to close to it and emotionally kind of thrown for a loop on this thing. Will drive great then suck, start shitty, then idle like a dream. Gets me up thinking I’ll be driving it to work again, then fails me in the morning when I try. Need more opinions that are further away from it.

I have some pictures and videos if you are wanting to see any of it. Unfortunately the truck is an hour+ away from me right now, but fortunately in more capable hands. For fresh photos, etc, will have to wait till Sunday at least when I could get over there.

[gard]

Did more research after posting. 2256 kPa = ~327 psi. 294 kPa = ~42 psi. I’m in the pocket there, 2 psi short on cylinder 3.


Only difference I can find is the block is taller for 4D56, different crank, and longer stroke. Nothing preventing the head swap from working? Right?

[dancinggecko]

Wow, that's a lot to take in. Starting with the compression test, #3 being 25 psi less than the rest isn't ideal, but is acceptable. The best thing you can do for your glow plugs is scrap the factory system and put in 12V plugs on a push button or something in the cab. You'll never have that temperature issue again. The biggest thing about the flush valve head on a motor that originally had a protruding valve is that it drops compression a tad bit, I have not run that setup, but have several protruding valve 4D55s and flush valve 4D56s and there doesn't seem to be any reason that the swap would cause problems. Do you have a fuel pressure gauge installed? I would be curious to know if your lift pump is able to keep up with your fuel needs or if it is starving the motor. I had that issue running a 30 gph pump so I upgraded to a 60 gph one. The rocker arm probably is a pretty big reason for your rough running. I would definitely check all of the valve lashes to make sure those are all good though.

[gard]

Thanks gecko. I appreciate you reading it all. I know it’s a lot, it’s everything. Work I’ve done and gotten help on are in different threads, but I felt the need to compile it into one place. Both for you guys and Both of those issues are in debate. The current plugs are 6v and I have a set of 12v brand new ones. My buddy and I discussed which ones would be best to wire up for the manual set up.

Out of curiosity how long and how many times do you work the glow plugs in different climate temperatures? Or is it based on the time the truck has spent resting as well?

We have also discussed the lift problem, because of how well documented it is here. I was thinking with a rebuilt pump I’d be getting it. But I’m not. The man who rebuilt it will be running the system on his table soon and we will find out.

My buddy has a kick ass electric pump from a 7.3 power diesel. He was thinking we could get a regulator and do exactly what psi/gph we want.
I’m going to scan all the manuals again in the fuel section and google for how much fuel we exactly need to be getting to the mechanical pump for it to be right.

[dancinggecko]

I'd recommend the 12V plugs, they glow hotter and are less likely to burn up on a 12V electrical system. I usually hold mine for about 5 ish seconds, but it depends on how cold it is. I'll also usually hit them a few times after it has started on a really cold day just to help things warm up. Do you still have the factory fuel filter/water separator mounted on the firewall? And where is your lift pump located?

[gard]

Yes it is the original fuel/water separator. Lift pump is mounted on the frame rail just in front of driver side rear tire.

[gard]

Got a new inquiry. When I am bleeding the fuel system my first point of bleed is the screw on top of the fuel/water separator. During the bleed process it sprays with some decent force. Out of curiosity I cracked it during operation and there was no fuel coming out. Anybody else ever crack that screw during operation?

[Bjamin]

Running a lift pump I'd think it would spit fuel unless the injection pump is pulling fuel faster than the lift pump is pushing (volume difference rather than pressure?)

[Topher]

I'm not of any help to you yet, but I want to thank you for posting your experience and following through. I am doing the exact same work right now. I got a 4D56 head, having turbo, pump, and injectors rebuilt. I will definitely be posting here when I get things back together, either to declare success or to try to solve a problem. Anyway, keep trying and let us know how it goes. If I run into anything which may help you, I'll post it.

[gard]

Yeah, that’s my thought too Bjamin. Already following gecko’s advice on a larger capacity lift pump. My buddy has a lot going on and hasn’t fooled with it this week. There is a thread by Unclespence that sounds similar, a misfire due to the injection pump getting too hot, which has to be from fuel shortage, because it’s cooled by the fuel. He confirmed the issue by driving it until the problem occurred and then poured a bottle of water over it and the problem stopped. Looking forward to running that test and getting the pump back to the rebuild guy. He is already prepared to make it right, though he is perplexed because it passed its tests before leaving his shop. Seeing as the problem is intermittent and is exacerbated by fuel starvation, I don’t know if he would have even noticed the problem in shop.

good luck Topher, let us know how it goes, and I’ll keep this thread going till it’s fixed and running. I’m too far in to stop now, hehe.