The cylinder head was more damaged than it first appeared, but I'd got the replacement valves, and had also missed out on a reasonable priced replacement, so I decided I'd repair what I had. I could always look for a better replacement, once the engine was up and running again. :eek:

The valve seats were actually out of round, so the valves wouldn't have sealed, without extensive cutting of the seats, which took me several hours, over a few days.
I used a new valve, a super size blue Sharpie, a sheet of 360 grit Wet n Dry cut into 8mm wide strips, oil for lubrication and some kitchen towel to block the ports.

The technique I used was simple, slow, but worked.

I started by "bluing" the seal face of the valve, then quickly inserting the blued valve into the port, so the seal face mated to the seat in the head. The valve was twisted a few degrees, then removed. The result was a blue "witness mark", where the Sharpie had transferred to the high spots on the seat. I then used the Wet n Dry to reduce the high spots by drawing the abrasive across the seat. I found that pinching the strips between the valve and seat, allowed lots of pressure to cut the seat back, just a fraction each pull. I repeated the mark and cut process until I had an even ring of blue, all the way round the seat. I then lapped the valves in the normal way, before cleaning everything up and reassembling the head.
The leaking No1 inlet lower port that I first and incorrectly diagnosed is the issue, was nothing more than a tiny piece of aluminium (I assumed from the piston), which was trapped between the valve and seat. It came out easily, and caused no damage once the valve was cleaned.
This is how the seats looked before cutting back.
20201125_115742.jpg

This is after cutting. The cutting back restored the seat to an even ring of matt grey, which it's supposed to have.
20201125_115806.jpg

I also smoothed down some of the jagged aluminium where the nut had impacted, but decided to leave as much metal as possible, to maintain the compression in the cylinder.

In all I'm happy that the head will remain serviceable for a while yet.:)
 
Wow that looks like some serious damage. that nut was brutal in there, and serious work to put it right, hats off to you nodge...
Do all the cylinders have the right compression now? What about the piston you replaced (no. 2) was it the same length etc??

Could the head still be faulty in some way??
 
Wow that looks like some serious damage. that nut was brutal in there, and serious work to put it right, hats off to you nodge...
Do all the cylinders have the right compression now? What about the piston you replaced (no. 2) was it the same length etc??

Could the head still be faulty in some way??

The damage was quite bad, but luckily the valve stems bent, which then allowed the valves to remain closed over the seats, which saved them from more damage. The aluminium was denied and chipped in places, but over all the amount of loss is minimal, I'd guess under 1cc.
The replacement piston was identical, from the same year of engine, but with half the miles, and is identical to the undamaged pistons.
I cross hatched the bore and fitted the piston after a clean in kerosene, and a good amount of lubrication.

I checked the bearing clearance with a Plastiguage, which showed a running clearance of around 1.7 thou, so that was good.

Due to the slight drop in compression volume of the cylinder, the compression will be down a bit, but when cranking, there's almost no difference between the cylinders, so the damage isn't going to cause an issue.

I don't believe cylinder No 2 (the damaged one) is the one causing the issue, but I'll do some more testing at the weekend.
 
Where do the injector nozzle and glow plugs sit...when looking at the cylinder head from inside as in your pics...does the spray come out of one-of those holes next to the valves???
20201126_160644.jpg
Are these where the injector or glow plug exits?
 
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Could the injector hole be blocked with molten aluminium??? Just a thought?

No, the head was given a thorough pressure clean and dry off with compressed air. All ports, oil ways and holes were cleaned and dried. I had to make sure all aluminium particles from the piston were cleaned off, so I cleaned everything properly.

The injectors protrude 8mm below the head face, so if the injector hole was blocked, that injector would be sitting high, but they're all even.

It's an injection issue, not the engine itself, that I'm sure.
 
Just a thought, its hard to see the level of damage to the head. Would you think there's a chance the different compression ratio for the damaged cylinder is an issue until warm?
 
Just a thought, its hard to see the level of damage to the head. Would you think there's a chance the different compression ratio for the damaged cylinder is an issue?

Not really. The amount of actual compression loosing damage to the head is minor. I don't have a suitable compression tester, but I have measured the battery voltage fluctuations while cranking on several occasions. The fluctuations in voltage were quite interesting at first, with there being a noticeable rise in voltage every 4th cylinder, which showed the No2 wasn't compressing as high as the other 3.
However the most recent test was after I'd completed about 50 miles driving and many hours of running at various speeds off load.
The voltage drop test now shows pretty even voltage drop per cylinder, with the low cylinder now indistinguishable from general variations in the voltage. So I think the initial loss of compression was through the piston rings, but those have sealed pretty well now.

I'll be doing another cylinder drop test (unplugging each injector in turn) tomorrow, so that will show which cylinder isn't contributing when the engine is cold. Last time it was cylinder No3 that wasn't working from cold, and I'm not expecting anything different this time.
 
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Good luck nodge ...it's good to see pics of the internal workings.

I've got loads of pictures, and some video footage too, where I was actually working on the bottom end. Unfortunately it's rather boring and the language is bit too blue at times to use.
I might edit and maybe voice-over some footage for YouTube.

There's nothing particularly different from this PSA engine, compared to many other 16 valve engines I've worked on.
 
It's running better.!!

Today I was naughty and unplugged each injector in turn while the engine was running. The engine was at 11°C, so reasonably cold. Cylinders No1-2 and 4 all stall the engine, cylinder No3 had no effect, other than log a code, just as the others did. I did notice that when I removed No2 injector plug, that there was a white puff of fuel mist, when I reconnected the injector, which suggested the seal (I reused the old ones, as I managed to put the new ones safe:oops:) was leaking slightly.

So I replaced the injector with an almost new, tested one, which was incorrectly listed on Ebay as being for a FL1 at a price of £33.
I also fitted a new washer to No3 which should be done every time and injector is removed (note to self there:confused:).

While replacing No3 I took the whole injector pipe off the rail, which isn't something I've done before. I noticed the the transfer port between the rail and injector pipe was tiny, literally 0.75mm tiny, and wondered if it could be blocked.
I connected up the new injector, hoping it was now sorted.
Well it was still running on 3 cylinders, just as before, which was annoying.

Next I coded all the injectors to the ECU, which resulted in it running no different.

I took it for a 3 mile drive, where it still had the heavy regular misfire under load, although it was now running an 4 while idling.

So I decided to remove No3 pipe and poke out that tiny hole in the rail transfer port. I figured the previous person to work on this engine managed to drop a nut into the intake, so how did store the rail while working on the engine? not carefully I figured.

At the same time I pulled out No2 injector, so I could replace the injector seal. The injector was wet with diesel, so it was obvious leaking slightly, so I cleaned out the injector hole, fitted a new seal and refitted the injector, and pipe from No2 and No3.

When starting the engine, it took ages to fire, requiring me to cycle the ignition 3 times, as it times out ofter 10 seconds or so. Once it started, the engine instantly sounded better, definitely running smoother than before. Unfortunately I did 2 things at the same time, which wasn't too smart. :(

Anyway the engine idled like a clock, so I decided to take it for a test drive. There's still a slight misfire/ surging thing going on, but it's nowhere near as bad as it was, as the regular heavy misfire under load has gone.
So tomorrow I'm going to replace the injector seals in No1 and No4, just to make sure those are sealed tight.
Hopefully the engine will run properly afterwards.
I'll be interested to see if it starts up on all 4 in the morning too, I guess time will tell.
 
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It's running better.!!

Today I was naughty and unplugged each injector in turn while the engine was running. The engine was at 11°C, so reasonably cold. Cylinders No1-2 and 4 all stall the engine, cylinder No3 had no effect, other than log a code, just as the others did. I did notice that when I removed No2 injector plug, that there was a white puff of fuel mist, when I reconnected the injector, which suggested the seal (I reused the old ones, as I managed to put the new ones safe:oops:) was leaking slightly.

So I replaced the injector with an almost new, tested one, which was incorrectly listed on Ebay as being for a FL1 at a price of £33.
I also fitted a new washer to No3 which should be done every time and injector is removed (note to self there:confused:).

While replacing No3 I took the whole injector pipe off the rail, which isn't something I've done before. I noticed the the transfer port between the rail and injector pipe was tiny, literally 0.75mm tiny, and wondered if it could be blocked.
I connected up the new injector, hoping it was now sorted.
Well it was still running on 3 cylinders, just as before, which was annoying.

Next I coded all the injectors to the ECU, which resulted in it running no different.

I took it for a 3 mile drive, where it still had the heavy regular misfire under load, although it was now running an 4 while idling.

So I decided to remove No3 pipe and poke out that tiny hole in the rail transfer port. I figured the previous person to work on this engine managed to drop a nut into the intake, so how did store the rail while working on the engine? not carefully I figured.

At the same time I pulled out No2 injector, so I could replace the injector seal. The injector was wet with diesel, so it was obvious leaking slightly, so I cleaned out the injector hole, fitted a new seal and refitted the injector, and pipe from No2 and No3.

When starting the engine, it took ages to fire, requiring me to cycle the ignition 3 times, as it times out ofter 10 seconds or so. Once it started, the engine instantly sounded better, definitely running smoother than before. Unfortunately I did 2 things at the same time, which wasn't too smart. :(

Anyway the engine idled like a clock, so I decided to take it for a test drive. There's still a slight misfire/ surging thing going on, but it's nowhere near as bad as it was, as the regular heavy misfire under load has gone.
So tomorrow I'm going to replace the injector seals in No1 and No4, just to make sure those are sealed tight.
Hopefully the engine will run properly afterwards.
I'll be interested to see if it starts up on all 4 in the morning too, I guess time will tell.
Glad to hear pal, never mind doing two things at once, you've been through the mill with this one so you are hereby forgiven :D:D:D. Good luck tomorrow.
 
Some good news John, at least you are moving in the right direction and it's starting to look like the issue is plumbing and/or a suspect injector.
I can't remember if I asked before but how much diesel was in the tank when you got it? I filled my van at a local fuel station a year ago and it drove terrible afterwards, especially cold. Just thinking it might be diesel related too.
 
you've been through the mill with this one so you are hereby forgiven
It's been tricky up to now, hopefully it's solvable tomorrow, or Monday, although I'd like to start changing the driveline fluids then.
It's going the right way!!!
You can now remove injectors with your eyes shut!!
You're not wrong Andy. ;)

Actually it's pretty easy to remove the injectors, which only takes about 5 minutes each.
Some good news John, at least you are moving in the right direction and it's starting to look like the issue is plumbing and/or a suspect injector.
I can't remember if I asked before but how much diesel was in the tank when you got it? I filled my van at a local fuel station a year ago and it drove terrible afterwards, especially cold. Just thinking it might be diesel related too.
Good news and bad Ali, but getting there I think.
I've just started it from cold, and it's still lumpy, but not as bad as it was, and within a couple of minutes, it was running smoothly, so it might be on the way to being sorted now. Just the last 2 injector seals to replace, and fingers crossed, it'll be ok, although I've sill no idea if the misfire is actually an injector, or just the seals letting the diesel escape to the outside. I'll see tomorrow.

It only had 1/4 tank when I bought it, but put another £25 to bring it home, I've put more in since, with come Diesel Magic, but it didn't help.

I'm pleased I bought the Mongoose Pro cable and you loaded SDD on that laptop for me, as it's been so helpful with calibrations and stuff.
I've coded the injectors, calibrated the throttle butterfly and calibrated the turbo servo too. Its also updated the CJB (the FL2 equivalent of the CCU), so has added the latest firmware, which has given me the 3 flash indicators my year was missing. I've also removed the CRASH status from the CJB, and calibrated all the windows and sunroof.
So thanks so much, I couldn't have done the diagnostics with your help.;)

These are complicated machines, so something like SDD is absolutely vital, if garage bills are to be avoided.
 
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Was the end of the other injector pipes as small as the one you said was 0.75mm?

The injector pipes are like normal injector pipes. It's only the rail outputs that have this tiny restriction in them. I've no idea what it's for, maybe to accelerate the fuel down the pipe? But it's possible it was blocked I suppose, although it didn't feel like it was blocked when I probed it.
 
It's been tricky up to now, hopefully it's solvable tomorrow, or Monday, although I'd like to start changing the driveline fluids then.

You're not wrong Andy. ;)

Actually it's pretty easy to remove the injectors, which only takes about 5 minutes each.

Good news and bad Ali, but getting there I think.
I've just started it from cold, and it's still lumpy, but not as bad as it was, and within a couple of minutes, it was running smoothly, so it might be on the way to being sorted now. Just the last 2 injector seals to replace, and fingers crossed, it'll be ok, although I've sill no idea if the misfire is actually an injector, or just the seals letting the diesel escape to the outside. I'll see tomorrow.

It only had 1/4 tank when I bought it, but put another £25 to bring it home, I've put more in since, with come Diesel Magic, but it didn't help.

I'm pleased I bought the Mongoose Pro cable and you loaded SDD on that laptop for me, as it's been so helpful with calibrations and stuff.
I've coded the injectors, calibrated the throttle butterfly and calibrated the turbo servo too. Its also updated the CJB (the FL2 equivalent of the CCU), so has added the latest firmware, which has given me the 3 flash indicators my year was missing. I've also removed the CRASH status from the CJB, and calibrated all the windows and sunroof.
So thanks so much, I couldn't have done the diagnostics with your help.;)

These are complicated machines, so something like SDD is absolutely vital, if garage bills are to be avoided.
I was just so pleased I could contribute in a tiny way to the repair and compared to what you are doing for me it was nothing. :)
 
The injector pipes are like normal injector pipes. It's only the rail outputs that have this tiny restriction in them. I've no idea what it's for, maybe to accelerate the fuel down the pipe? But it's possible it was blocked I suppose, although it didn't feel like it was blocked when I probed it.


I think if it was blocked you would soon know about it, any metal particles in a common rail sysetm will kill it dead.
All the newer trucks are common rail, and even the fuel filter changes have to be done in a certain way to stop swarf etc getting into the rail, weirdly there is always evidence of swarf/small shiny metal particles in the bottom of the fuel filter bowl, shine your torch in there and it looks like you are panning for gold!
I would love to slag them off, but they are all now on a million kms so cant be all bad, though they have literally cost a small fortune to keep going in them million kms, I certainly would not buy one!
 

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