P0299...and an occurrence of P0234!

greiswig · **Posted:** Mon Mar 24, 2014 2:06 pm

Hi, all,

It's been awhile! I have 134k on my 2005 CRD now, and most of it has been uneventful and reliable. I have run the EHM mod on it since about 5k, and I have the INMotion tune that minimizes EGR usage.

Recently one of the glow plugs gave up the ghost, and I have been waiting for decent weather and a day to go ahead and replace all 4 ceramics with metal-tip units. Meanwhile I just put up with the CEL. But...

I had an incident last week that caught my attention: idling at a stop light, suddenly there was a long "beep" from the dash, and every light on the dashboard lit up. So I pull into a parking lot and scan. I get the 1263 code for the glow plug, but then also a P0299 code; turbo underboost. Hmmm...how long has that been there with me assuming it was the glow plug?

So on the way home, I tested it a little: I put my foot in it on a highway, and it immediately threw a code and lost most power. No smoke, though. No wheezing noise like I would expect from a major turbo hose leak. From that point until I got home, there was no difference at all between half-throttle and full throttle. So I assume I was in "limp home mode?"

So over the weekend I opened things up. Here is a list of what I have done so far:
-I replaced the fuel and air filters.
-I disconnected the turbo hose at the FCV and plugged it, then disconnected the hose at the turbo and blew into it: no hissing noises, and no apparent loss of pressure. I know...I'm a blowhard, but not a 15PSI blowhard, so this probably isn't a great test. But if this were the issue, I wouldn't ever expect to see an overboost code.
-I did a visual inspection of vacuum hoses, and checked for leaks by plugging one end and sucking on the other (no comments, please) and making sure they held vacuum.
-I cleaned the MAF sensor with MAF cleaner
-I cleaned the MAP sensor with MAF cleaner
-I disconnected the pressure sensor that is in the air filter box (is that a MAP sensor?), and checked resistance across the various terminals, including when I was sucking and blowing into an attached piece of vacuum tube...no change in resistance according to the pressure, but perhaps this unit doesn't work that way?
-I wiggled the inlet turbine on the turbocharger. There is a little play, but not much. I didn't seem to be able to make it bind up or anything. No idea how or whether I could check if the variable vanes are working properly or not. Very little oil in there, and no carbon buildup that I could see, at least.

So. Any ideas what I should be looking at next? I ordered a new MAP sensor (the one that goes on top of the intake manifold itself), since they are fairly cheap and might cause all kinds of problems if they are bad. I appreciate any help!

papaindigo · **Posted:** Mon Mar 24, 2014 2:45 pm

At 134K I hope you have done the timing belt job if no park until it's done. That PSA said...

1. every dash light coming on sounds like a battery hiccup. Check terminals for corrosion/loose; check chassis grounds; load test battery; check alternator output.
2. you can pressure test the CAC hoses and intercooler on the engine but doing it by mouth so to speak; you would have to plug one end/cap the other with something that will let you induce no more than 15 or so psi from a compressor. I'm NOT recommending that method. Bet to pull the hoses off the vehicle and inspect the bottom side for cracks or tears, replace, if soggy with oil like a sponge, replace.
3. P0299 can be boost pressure solenoid; try the bypass viewtopic.php?f=5&t=70602&p=757348&hilit=boost+solenoid#p757348 if that does it replace. Can also be bad vacuum line see viewtopic.php?f=5&t=61240
4. to check turbo vanes 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 moevment."

greiswig · **Posted:** Mon Mar 24, 2014 4:11 pm

papaindigo wrote:

At 134K I hope you have done the timing belt job if no park until it's done. That PSA said...

1. every dash light coming on sounds like a battery hiccup. Check terminals for corrosion/loose; check chassis grounds; load test battery; check alternator output.
2. you can pressure test the CAC hoses and intercooler on the engine but doing it by mouth so to speak; you would have to plug one end/cap the other with something that will let you induce no more than 15 or so psi from a compressor. I'm NOT recommending that method. Bet to pull the hoses off the vehicle and inspect the bottom side for cracks or tears, replace, if soggy with oil like a sponge, replace.
3. P0299 can be boost pressure solenoid; try the bypass viewtopic.php?f=5&t=70602&p=757348&hilit=boost+solenoid#p757348 if that does it replace. Can also be bad vacuum line see viewtopic.php?f=5&t=61240
4. to check turbo vanes 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 moevment."

Done the timing belt. New alternator is on the way, as I'm pretty sure I hear a pulley about to go bad.

I'll try bypassing the boost solenoid...thanks for that.

I have checked the play on that turbo actuator: it looked more like 1/4" to me, but mostly what I was trying to see was whether it was moving at all. Is that 1/2" really the expected travel? If so, I'll have to look more closely.

Thank you very much for the input!

papaindigo · **Posted:** Mon Mar 24, 2014 4:26 pm

GDE says about 1/2" but I have no way of checking as I, see my signature, don't have the stock turbo. Best I can say is if you saw it move some then it's working at least partially so it's likely not related to your significant issue. Once you cure the significant issue I'd suggest an "Italian" tune-up (get engine up to full operating temp and do say 3 full throttle acceleration runs up a mild slope like an interstate on ramp type grade - burns off the soot that tends to make the vanes stick) to make sure the turbo vanes are free.

greiswig · **Posted:** Sat Jul 26, 2014 3:39 pm

So...I am still contending with this issue. I replaced the glow plugs because one of them was bad, and while it was at it I cleaned the flow control valve and intake elbow. This engine is using a Kennedy lift pump, which had also gone south, so I fixed that as well. It also has an InMotion tune.

I am still throwing codes. 299 (turbo underboost) is the usual culprit, and it does it most often when the engine is not yet warmed up fully. However, I can also get it to throw a 234 (turbo overboost) code by putting my foot in it on a steep hill. Once it has thrown that code, it goes into limp mode and drives...limply. Until it is cleared.

I have tried hard to check for obvious leaks in the boost hoses and intercooler, and can't find any. I suppose it is possible that the intercooler is clogged with oil and soot, but I have been running the ehm since the engine was pretty new, and there actually wasn't much deposit on the FCV. So I kind of doubt that is the issue.

The odd combination of codes, overboost and underboost, also has me puzzled. Can anyone point me in the right direction? Right now, this is utterly useless as a tow vehicle, because it will just throw the 234 code and go into limp mode if it is towing anything substantial.

Thank you!

Mike92104 · **Posted:** Sat Jul 26, 2014 5:18 pm

I would check for something shorting out in the wiring.

greiswig · **Posted:** Sat Jul 26, 2014 7:01 pm

Mike92104 wrote:

I would check for something shorting out in the wiring.

Any idea what the primary sensor or sensors are driving this? I have replaced the MAP sensor that is mounted to the intake manifold, but not the one that is on the air filter box. Those are the two, I would guess.

Mike92104 · **Posted:** Sat Jul 26, 2014 7:17 pm

That's where I would start, but it could be any of the sensors. I would suspect areas where the wiring comes into contact with something else. Start by looking for visible damage to any of the wire looms or sheathing. Take your time.

I can't remember if it's the 2006 model or 2005 model, but the was an issue with the wiring being chaffed behind the fuel filter that caused all sorts of strange computer problems.

Good Luck,
Mike

thermorex · **Posted:** Sat Jul 26, 2014 8:36 pm

I wonder if your valve cover elbow, that is after the intake elbow you just cleaned, doesn't have lots of soot... You'll have to look through with a mirror after elbow is moved.

greiswig · **Posted:** Sun Jul 27, 2014 11:08 am

I'll take a look at the loom, and I appreciate your suggestions. The thing is, I wouldn't expect an electrical issue to act this way: the 299 code goes off pretty quickly, but in order for the 234 code to go off I have to really put my foot in it.

When I had the FCV and elbow off to repair the glow plugs, I did poke my finger up into the intake manifold to see how clogged it was, and it didn't seem to be any more clogged than the elbow itself which only had a thin coat of soot and oil on it. Worth cleaning while I had it out, for sure, but totally inconsequential in terms of its ability to affect the airflow.

At 140k, might there be any other wear issues that could cause this that I should be aware of?

SargeIndustries · **Posted:** Mon Jul 28, 2014 3:22 pm

it sounds to me like your turbo is sticking and it is under boosting at low throttle and over boosting high throttle. I ran through this problem a few weeks ago. I removed my turbo disassembled and carefully freed up each pivot point on the little wings. Do not use pliers to free up the little wings inside or you may break one off. I have also heard that you can use Hoppes gun cleaner to soak over night and it is suppose to do a very good job of cleaning.

Topan · **Posted:** Tue Jul 29, 2014 12:05 pm

Hi , my 2 cents comment:
I had a p0299 fault . Took me weeks to find out that the vacuum line had got too close to the engine part and melt down. Section between the solenoid and going underneath the panel. The section that melted was protected by a rubbed alu hose...
viewtopic.php?f=5&t=61240

Maybe you moved around the vacuum line while working on the plugs.
I would check them all thoroughly .

greiswig · **Posted:** Tue Jul 29, 2014 10:22 pm

Well, I tried the Easy Off approach overnight, and it didn't change a thing. So today with some helpful advice from a friend (thanks, Mitchell!) I pulled the turbocharger off. Pulling it apart, 3-4 of vanes were seized tight in their hole, and one of the three roller bearings the actuator moves across was also seized.

It wasn't carbon as far as I could tell. There was no evidence of carbon to speak of, where I would expect to see buildup that is hobbling the vanes. Nothing like that, just seized up as though there was corrosion. There is enough axial play that careful tapping with a wrench extension will start them moving, then you can start to work penetrating lube into them and work the kinks out.

I think the 1/4" of play I was seeing in the actuator was just play, and nothing was actually moving. So I will be cleaning everything off, putting some graphite on the bearing surfaces I can reach, putting graphite lube in the holes I can get it into.

This is a tricky thing, for sure, but it should help. I think the 299 and 234 codes were completely accurate.

Auberon · **Posted:** Wed Jul 30, 2014 11:37 am

Parts if the manual (chapter 9) do suggest that they will occur together.
Hope you got it.

greiswig · **Posted:** Wed Jul 30, 2014 3:37 pm

Auberon wrote:

Parts if the manual (chapter 9) do suggest that they will occur together.
Hope you got it.

Well, in this case the vanes were locked in about mid position, so it was out of tolerance on both ends of the boost spectrum. If I had a boost gauge, I would have verified that much earlier.

Meant to mention: about .0035" axial play, and barely perceptible radial play in this. I could not persuade either set of blades to contact the housing. Also, the total movement of the actuator once I freed everything up and reassembled is 11-12mm. Previously, there was perhaps 1/4", but I think that was just slop in the system or else the actuator arm had come out of the control ring. None of the vanes were moving, that's for sure.

Hope this helps someone else. I sure appreciate all the help I've had from this group.

P0299...and an occurrence of P0234!

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