OM642 Misfire and White Smoke

[hamodi]

It's oil. The EGR was also drenched in oil. Cylinders 4,5,6 no compression. Cylinders 1,2,3 compression ok 30bars. I guess the cylinder head is coming off. Still don't understand what happened...

 

[alexanderfoti]

It's oil. The EGR was also drenched in oil. Cylinders 4,5,6 no compression. Cylinders 1,2,3 compression ok 30bars. I guess the cylinder head is coming off. Still don't understand what happened...

If three cylinders no compression, then likely to be head gasket. All will be revealed with the heads removed.

 

[Uncle Benz]

If all this started with removal and refitting of the high pressure pump and now all cylinders on that bank have no compression I’d be suspicious that something on the camshaft drive has gone badly wrong. One cam is driven by the chain, the second cam is driven by a gear from the first cam. The high pressure pump also drives off those gears. I’m worried something has broken in there.

 

[alexanderfoti]

If all this started with removal and refitting of the high pressure pump and now all cylinders on that bank have no compression I’d be suspicious that something on the camshaft drive has gone badly wrong. One cam is driven by the chain, the second cam is driven by a gear from the first cam. The high pressure pump also drives off those gears. I’m worried something has broken in there.

Ah yes good spot, didn't see that. Maybe a rogue screw as op mentioned screw loose?

 

[hamodi]

Yes I am extremely suspicious as cylinders 4,5,6 are on the same side as the high pressure diesel pump. Valve cover will come off today and we’ll see if anything obvious, I’ll check the timing then move on to the head if nothing obvious.
When cylinder 1,2,3 valve cover was removed to time the pump to TDC cylinder 1, it was confirmed that timing was ok on that side and timing chain not stretched.
Will keep you guys updated. Thank you all for your input.

 

[alexanderfoti]

Yes I am extremely suspicious as cylinders 4,5,6 are on the same side as the high pressure diesel pump. Valve cover will come off today and we’ll see if anything obvious, I’ll check the timing then move on to the head if nothing obvious.
When cylinder 1,2,3 valve cover was removed to time the pump to TDC cylinder 1, it was confirmed that timing was ok on that side and timing chain not stretched.
Will keep you guys updated. Thank you all for your input.

Ah great, at least you have confirmation that the cam was moving when the pump was changed.

Did the problem occur immediately after replacing the pump or did the car run OK for a while?

 

[hamodi]

The cam is moving for cylinders 1,2,3 but I’ll found out about 4,5,6 after taking the valve cover off. Although, if the chain isn’t stretched and timing is ok for 1,2,3 it’s hard to imagine how it wouldn’t be for 4,5,6.
Immediately after starting the car with the high pressure fuel pump replaced these problems occurred with rough idle and white smoke.

 

[alexanderfoti]

The cam is moving for cylinders 1,2,3 but I’ll found out about 4,5,6 after taking the valve cover off. Although, if the chain isn’t stretched and timing is ok for 1,2,3 it’s hard to imagine how it wouldn’t be for 4,5,6.
Immediately after starting the car with the high pressure fuel pump replaced these problems occurred with rough idle and white smoke.

Aha, there in may lie your issue as Uncle Benz

 

[hamodi]

Got all the way to removing all the valve cover bolts but it won’t budge no matter what I do. Is there a special tool or procedure for removing the valve cover? Thanks.

 

[Uncle Benz]

You've got all the bolts? There are some in the middle that are easy to miss. The cover holds the cams down too, so be careful. The covers are sealed to the head with sealant, no gasket is used. They can need a bit of persuasion. The cam cover and head are a matched set, so make sure all the bolts are out first. There are lots.

 

[hamodi]

Yes, double checked and had a friend look with me. All bolts are removed from the valve cover.

 

[hamodi]

Was so busy this week, only got to remove the valve cover tonight. Looks like all the intake valves are broken

 

[Uncle Benz]

The mesh of the two cam sprockets looks wrong. The cam has slipped timing to cause that much damage.

 

[alexanderfoti]

Is there any damage on the cam gears?

 

[hamodi]

Thanks guys, I'll have a look tomorrow morning in daylight. I'll confirm but it looked like the intake cam gear was slightly bent as it didn't mesh evenly with the exhaust cam gear or the diesel pump.

If the rocker arms are broken, is it worth performing a leak down test to determine whether they broke and my valves sprung shut without taking hits from the piston bending valves? Or am I being too optimistic and I should just remove the cylinder head? Doesn't explain the oil in cylinders 5/6 though...

 

[alexanderfoti]

They would have broken the rocker arms when thr pistons hit the valves. Unfortunately, it will be ver unlikely that you will have no damage. It will be head off job either way. The oil will be from reversion, or the cylinder has been holed by the valve which is unlikely.

 

[Uncle Benz]

As Alex says, valve damage is very likely. Piston damage cannot be ruled out either. If a valve head has broken off it can easily punch a hole in the piston, although I'd have expected you to hear that kind of catastrophe. The way it was chuffing in the video clip you posted I'm worried about the piston(s). One way or another I think the head will need to come off.

 

[Uncle Benz]

Long and short of it though, I'm certain the root of the problem lies with that diesel pump. Either something came off it and got jammed in the gear or it wasn't meshed properly when it was reinstalled. Pushing the pump into place is performed blindly. It's a gentle fiddle and caress to get the sprockets cleanly meshed. If the pump was roughly placed in the hole and then dragged in with the bolts I could perhaps see something like this being the result.

 

[LostKiwi]

That looks quite possibly scrap.

 

[hamodi]

It’s as Uncle Benz said, I think pump was fitted wrongly and bent camshaft pulley slightly. However, I have checked the timing and the intake and exhaust camshafts line up (timing is correct). I think it may have been in the moment of first starting after diesel pump fitted that the incorrectly meshed pulleys put pressure and broke the lifters. Valve springs still intact, just the rockers are broken.