Loss of power issues

kjjon81 · **Joined:** Wed Aug 07, 2013 1:26 pm **Posts:** 30

I have a problem with my 05 crd with a green diesel tune.
I was driving home at 65 mph on the highway when I had a loss of power and threw a P0234 code(Overboost)
The CRD in park revs fine but when driving(under a load) it the engine clatters when approaching 2000 rpm and black soot exits the tailpipe.
I pulled the hoses off the turbo no play in the turbo.
I then went to the vacuum pump and hooked up the gauge to see what it was reading. about 13 in.hg at idle and 5 in.hg when you hit the gas.
I did a pressure check of all of the intercooler hoses and the intercooler.
Pulled the battery cable off the battery for some time reconnected it and I still have the same condition.

If anyone could send me on the right path for my troubleshooting strategy it would be greatly appreciated

Thanks - Jon

greiswig · **Posted:** Tue Oct 14, 2014 12:39 pm

On my rig (no GDE tune), the 0234/0299 code was telling me the truth: my turbu vanes were locked in one position, so it was overboosting in some situations, underboosting in others.

In your case, something seems wrong: black smoke is a symptom of running too rich, i.e. underboost. Overboost also wouldn't cause a perceptible loss in power, I don't think. So I'm not sure what is going on for you. I would expect it to have a P0299 code instead, with black smoke and loss of power. Are you sure you read all the codes?

On my rig, too, overboost may have caused some engine damage (cylinder head crack). So I would start by making sure that the actuator arm on the turbo is working properly...not because it is the most likely place for the problem, but because that seems to be a place where not fixing it quickly may cause more severe problems. Easy way to check (if you have a MityVac or similar tool) is to unhook the hose to the actuator and make sure that it moves smoothly about 12mm or so. If so, you may want to look at the air solenoid that is in series with that, although I would expect that to fail in a way that causes underboost, not overboost.

If the turbo seems okay, just do a search on this forum for P0234, and you'll find a wealth of information. Report back on progress and we'll try to help more.

flash7210 · **Posted:** Tue Oct 14, 2014 2:51 pm

Bent or broken or worn out rocker arms maybe?

papaindigo · **Posted:** Tue Oct 14, 2014 3:18 pm

No power; black smoke; no turbo play; can I assume you have checked the oil level. Thoughts:
1. I know you have pressure tested the CAC hoses but I'd pull them off and do a physical inspection anyway, especially on the bottom side.
2. check turbo vane function as suggested or per GDE "You can check the vane functionality at idle in park. Underneath the vacuum actuator on the turbo is rod extending downward connected to the vane mechanism. If you pull off the vacuum line at the turbo, the arm should drop about 1/2 inch and then raise back up after reconnecting the vacuum line. It is a bit difficult to see the rod, but this is the easiest method to check for proper VGT vane movement."
3. do boost pressure solenoid bypass - see viewtopic.php?f=5&t=70602&p=757348&hilit=boost+solenoid#p757348

How many miles on the rig and have you done the timing belt change?

kjjon81 · **Joined:** Wed Aug 07, 2013 1:26 pm **Posts:** 30

I completed the removal and reattaching of the vacuum line and found that it was only budging maybe a quarter of an in it's hard to tell how much it actually moves .. Didn't have much time today will report back tomorrow - cheers

greiswig · **Posted:** Wed Oct 15, 2014 8:05 pm

So the next question is this: is it a vacuum leak or problem, or is it the turbocharger?

That's where the tool I mentioned before would help.

kjjon81 · **Joined:** Wed Aug 07, 2013 1:26 pm **Posts:** 30

Applied a outside vacuum source that reached 22 in.hg and the movement on the actuation arm for the turbo was minimal maybe 1/8 - 1/4 of an inch it certainly wasn't the half of an inch described by other members. So I guess its time for a new turbo.....

papaindigo · **Posted:** Thu Oct 16, 2014 1:08 pm

No it's not time for a new turbo; that would only be the case if the "fan" just inside the front of the turbo had excess play (fore to aft slight play; side to side barely perceptible play - is so it's fine). What's needed is a) an Italian tune-up - get system up to operating temperature and do several full throttle accelerations up a slight grade like an on ramp while ignoring clouds of smoke behind you, hopefully this will burn off the soot that's causing the turbo's variable vanes to stick but if not b) you will need to clean the variable vanes. Unfortunately I have not saved copy of or a link to a post on how to clean but I do remember it involved the use of Easy Off oven cleaner. Hopefully someone who knows the details will post but if not you might want to do a new post asking the question re. suggestion b)

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

The only sure fire way to de-soot the turbine vane linkage is removal of turbine and cleaning. Not sure you can get the oven cleaner up into the linkage area well as it is mostly shrouded up inside the turbine around the perimeter of the turbine wheel. It is worth a shot though.

After a good soaking maybe you can work the linkage a bit with vacuum and light pressure. Don't give it too much force or the rotating part can fatigue fail.

greiswig · **Posted:** Thu Oct 16, 2014 1:46 pm

For a change, I am going to disagree with papa.

I think the italian tuneup method may have helped cause some of my gasket leak and/or head crack issues. Not positive, but there was correlation so there may be causality. My thinking is that the over boost condition may have been such that it lead to those failures.

Moreover, the vanes in my turbo were stuck in the bearing area (the shafts that connects the actuator wheel to the individual vanes), so no amount of lead footed driving would ever have freed them up. There was virtually no evidence of carbon on the surface where it would bind the vanes. It all seemed to be in that bearing area. Made it a bugger to free them up without breaking the welds on those shafts, but only 6 of them were binding.

It is not that hard to remove the turbo, open up the exhaust side, and free things up. It isn't trivial, but it's a lot less work than replacing a head or head gasket. And it's free!

If you are pretty sure your vanes are sticking, that seems like the safer approach. Just a thought.

papaindigo · **Posted:** Thu Oct 16, 2014 2:11 pm

George - I'm not going to disagree with you or at least not much. In your case IIRC there was no movement of the actuator shaft but in this case there is some movement. That implies to me, correctly or not, that the vanes are moving some in which case an Italian tuneup might have a decent chance of freeing them. That said I view the Italian tuneup as something that should be done from time to time as a preventative measure especially for those of us who don't put miles or our CRDs like we used to.

As for freeing up the vanes by method b) how, step by step did you go about doing it? Wish I had looked at my OEM turbo when I swapped it out but it's long gone to another member whose turbo had shaft play. Do you have to pull the turbo off and open the exhaust side up or can you get enough access by undoing the marmon clamp on the exhaust and dropping the exhaust pipe a bit? I sort of have a vague memory that the latter was possible. I mention this not because the turbo is all that hard to pull but rather because of the fragile nature of the 4 studs that attach the turbo to the exhaust manifold (geordi and I had a real problem with them when we installed my GDE turbo).

greiswig · **Posted:** Thu Oct 16, 2014 2:23 pm

No, there was movement in my actuator. I tried to make that a point elsewhere, that I had what appeared to be nearly 1/4" of movement. But that was just system play before the vanes actually moved. That's why it is important to measure the actual movement, and make sure that it is >12mm. That ended up being only a bit over a 6mm difference in what I could see when trying to gauge the difference with the turbocharger installed, so it's not easy.

I basically took mine apart altogether, sprayed fluid lock lubricant (with graphite) into everything and let it soak for a bit, then worked the stuck vanes by fingers until they freed up.

I don't think you could do what I did without removing the whole thing.

Loss of power issues

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