Turbo Blues

I have a 2004 T1N with 260,000 miles. It is intermittently going into Limp Home Mode, as appears to be a common situation on the forum! It can run for hours, with good turbo boost , with no problem, but then out of the blue, it looses boost (or at least it goes down to about 1.5 to 3 pounds) It doesn't have to be under high turbo load when it happens....it can just as easily be cruising along on the highway at 60mph and not accelerating at all. It is failing with a P2359 code, which is low/high turbo boost pressure, but with no other codes present.

My mechanic thinks it is the turbo vanes being coked up and sticking, or the actuator failing. I had him lube the actuator arm, as a number of people have had similar issues, and that was their solution, but it does not appear to have resolved the problem. I am thinking it is unlikely to be a hose/resonator or a sensor problem, because of the single code, and the fact that it is not happening on high boost...and that it can run at high boost for hours without the problem manifesting.....seems to me a leak would happen faster and more readily at high boost pressure.

My mechanic said I should buy a new actuator / turbo assembly, but the cost is pretty crazy (especially since I have done a whole new cylinder head and EGR in the last 12 months!) XSBoost seems to be a good source of rebuilds ($750), but they are currently out of OM647 turbos (they have new ones at about $1250).

So I am currently leaning towards starting by getting the Actuator rebuilt (about $200-300). There are a couple of guys that do this on the internet. It seems to me that that is the most likely source of the problem, VS the turbo veins being coked up. People seem to say that the turbo itself is pretty bullet proof. Can anyone comment on this?

I do have a couple of questions about removing the actuator to send it in to be re-built. Can it be done without removing the entire turbo assembly? That would save at least a couple of hours of time. Also, I have read that the electronic actuator is self adjusting, so re-installing the new/rebuilt actuator should not be a problem. As I understand it, the Vacuum actuators have to be "zeroed" in on a bench, but not so with the electronic one. Can anyone confirm this?

My second issue is that I do in fact have access to a brand new Garrett Turbo GT 2256V turbo, with a vacuum actuator. The unit was advertised as a direct replacement for the 2004-2006 Sprinter turbo, and it was cheap, so I bought it a while back as a spare, but when I got it, it had the wrong actuator. I have attached a picture...it looks like the actuator used on the UK and Euro Sprinters (OM612 perhaps...). However, the turbo body itself looks like it would work. There are a whole bunch of people on EBAY selling the same unit (generally with no actuator) in the 300-500 dollar range, as replacement turbos for 2004-2006 Sprinters. ....I assume someone must be buying them and using them..... So, I am wondering...If I get the actuator re-built, but it doesnt solve the problem, could I slap the actuator on this turbo, and put it on my T1N....has anybody out there bought one of these from ebay and put on the electronic actuator?

Any thoughts....or disagreement with the direction I am taking?

Rick

You'll see this recomendation in hundreds of other posts. Odds are good that you have an air leak in the Turbo hoses or Turbo Resonator (2004 - 2006's only). Please look for oily patches on the Turbo hoses. I would suspect the Turbo Resonator, since what your are seeing seems to be how it responds when a Turbo Resonator gets cracks in it.

The Sprinter turbos don't fail that often.

People who don't work a lot on Sprinter Boost issues tend to assume the Turbo has somehow failed - usually, its fine.

X2 on that jmoller99 said. Boost leaks are the most common cause of boost pressure codes.

Even if the turbo linkage is sticking, it can be cleaned and/or worked loose. The actuator will nee to be disconnected before attempting this.

X3 on "it's the turbocharger" not being your problem!
Think about what you have told us.
#1 Turbo puts out near normal boost most of the time, except when it pops and goes into LHM.
If the turbocharger was bad/worn out, it would never make any pressure, so that pretty much cannot be your issue here.
#2 Mechanic thinks the turbo vane ring is "coked up" and is not turning smoothly.
If this were the case, you would never get normal boost and the amount of force required to turn/move/adjust the
turbo vane ring can very easily be checked out by simply disconnecting the link to the electronic actuator and
turning the bell crank on the front of the rear cast iron "hot" chamber in your turbocharger.
If it turns fairly easily and smoothly with no hang ups put a little liquid wrench on the bell crank shaft and re attach
the linkage to the actuator.
#3 If the electronic actuator is not working correctly, then you most likely would never get anything like normal turbo
boost pressure as the actuator is what controls the vane ring and causes the vane ring to turn in the turbocharger the
increase/decrease the boost pressure level.
Have to agree with the others here....you have a boost leak somewhere. It only leaks when you reach a certain
boost level....then the ECM cuts off your boost to save your engine.
Find the leak....repair the leak.....all without changing anything in the turbocharger or actuator.
How hard is it to manually palpate (squeeze with your hands) the turbo hoses? Any soft spots are most likely
indicative of some level of hose failure.
Check all the hose clamps to ensure that they are tightened enough to retain the hose (on both ends) to the
Resonator, the Charge Air Cooler, the MAP mounting plastic box and the intake horn on your engine.
And, as suggested above, remove resonator and really inspect the top seam.
Heck buy one of the Dorman replacements for < $40 and see if that takes care of the problem.
Or, visit a MB/FL Sprinter dealer with the MB SDS diagnostic tools (or a high end independent shop with the requisite
diagnostic capabilities) and have them run the live system checks, as well as read the codes stored in the ECM
memory.
The dealer will want to replace the entire turbo and actuator (even if there's nothing wrong with either of them,
that's just what their guidance tells them to do) but just get the results of the diagnostics.
A recurring stored code for either high or low boost will help you to understand that your issue is most likely a
simple boost leak in one of the hoses or units (resonator/CAC/MAP box) or one of the hose to unit connections.
Oh yeah, you cannot put a vacuum powered turbo actuator on a 2004-2006 OM 647 engine.
The earlier OM-612 engines used the vacuum powered actuators, but the OM-647 uses the more advanced
electronic powered and controlled actuators.
Hope this helps,
Roger

OK...seems unanimous. I still don't quite see how a leak in the hose or resonator would allow me to go to full boost and drive flawlessly for hours, and then suddenly produce a fault when I am nowhere near full boost.....but I don't think it pays to ignore the assembled knowledge of the group! There is probably a good payback in replacing the hoses and especially the resonator anyway, in terms of future reliability, and it is the cheapest thing to do, so I like that!

I will update the thread with the outcome once I have something to report.

Rick

Rickster22,
If you have a Scan Gauge II (or similar) and are monitoring the MAP (Manifold Absolute Pressure) or BST (Boost pressure in PSIG) and you see the full 35-37 PSIA MAP or
20-22 PSIG Boost (BST) then you may be on to something.
Without the quantitative values for MAP/BST how do you know you have "full boost"?
Just a small change in the road gradient, or attempting to accelerate can run the % engine Load to the maximum, and unless the turbo can develop full boost pressure
the ECM shuts the turbocharger off as an "under boost" incident.
If you pull over, shut off the engine, and restart it and the boost is restored, there's nothing wrong with the entire turbo system,, but there is a leak somewhere that is
preventing the full boost pressure from reaching the MAP sensor.
There are some other things but this is the most likely scenario.
Only a full diagnostic scan (both live data and ECM historical) can give you all the information as to what the issue is, then you need to determine if it's a leak, and
out of tolerance sensor, or something else that you would never guess is related without the diagnostics.
Hope this helps,
Roger

If you are really getting random error codes, you it might not be a leak, but that is the first and easiest place to look.

After that checking the various sensors (MAP, MAF etc) is a good option.

There was a post on this forum a few months ago where a user found 2 cracked connectors inside the turbo actuator, it causes some odd issue for him. I will try and find the post. He fixed it by soldering a new set in.

If the turbo is mechanically failed, you can visually inspect it. The compressor wheel is visible with the intake tube removed. The vane linkage can be disconnected and moved by hand, etc.

'P2359 code, which is low/high turbo boost pressure'

Often the MAF sees a lot of air move thru it, but does not see a corresponding pressure at the MAP sensor. Somewhere between the MAF sensor (which gets air sucked thru it by the turbo) and the MAP sensor (on the Plastic part that the last turbo hose connects to before attaching to the intake manafold) - the air pressure was lost - usually somewhere between the MAF and the intake manafold.

If you let someone change your Turbo and it doesn't fix the problem, odds are good you won't get a refund for the expensive mis-diagnosis.

I second the reccomendation for a ScanGauge II or an UltraGuage EM. I watch my Boost and MAP pressures while driving, as well as the intake air temp. I know what is normal for my Sprinter.

The EGR can also be carboned up, and it might not throw an error (but often does). The EGR can be cleaned (Don't take the EGR apart!).

I was able to record some values using TORQUE and an ELM ODB reader at the point of the last time it boosted, and then went into limp mode. Not completely sure what to make of it. I wonder if the issue is the drop down in MAF value (green line), with intake and turbo pressure staying constant. I guess that might indicate a small leak that was enough to trip the ECU into shutting down.

Torque is a good tool, but I wish it would let you record and graph more variables over a longer term, and then work with the stuff off line.

What is the LH column of numbers...what units?
0.0 to 250.0 Manifold Absolute Pressure for Intake Manifold Pressure
0.0 to 250.0 Mass airflow in what units.....CFM or some metric units?
0.0 to 250.0 Turbo Boost Pressure.....should this not be Intake Manifold Pressure - 14.7 PSIA (1 atmosphere)
Your Torque App Chart is kind of confusing.
Roger

Get an Ultragauge or Scangauge. By monitoring Manifold Absolute Pressure, my UG recently diagnosed an intermittent limp mode while underway on the Hope Princeton. By Keremeos, I'd figured it out without even opening the hood. Boost hose intermittent leak. Easy DIY fix.

The units for boost must be PSI.. The boost pressure is showing a bit less than half way between 0 and 50...probably around 18-20....which is what I have been seeing as about my maximum boost (I think the highest I have seen it was about 22). Again, TORQUE doesnt really explain what it is doing....in the configuration, it has a parameter for "Boost Adjustment" and it says "usually -14.7, 0, or 14.7 (atmospheric pressure adjustment at sea level)". Right now, that is set to 0, so I guess that would be the absolute air pressure. I am at sea level. If I understand it right 22lb seems a bit low....do you know the correct range for turbo boost on a sprinter?

MAF seems to be "g/s" whatever that is (gallons per second?....no clue!), and Intake Manifold seems to be in kPa (kilo Pascals, I guess)

Unfortunately, TORQUE doesn't have much in the way of documentation or explanation...it picks the units, and it picks the scale....

Hi Rickster 22,
it has a parameter for "Boost Adjustment" and it says "usually -14.7, 0, or 14.7 (atmospheric pressure adjustment at sea level)".
Usually the PID (Parameter Identification) code for Boost is "BST" and is measured in PSIGauge. So it doesn't change with altitude, it just simple pressure.
Of you decide to measure Boost (BST) the normal range is 0.0 PSIG to ~21-22 PSIG.
If you decide you like to use the same units and system that your Sprinter has a sensor for, then Manifold Absolute Pressure (MAP) is the PID.
With the engine off, @ sea level (no altitude) your Torque should read right around 14.7 PSIA (1 atmosphere @ sea level) and run in the range up to
~36-37 PSIA.
Right now, that is set to 0, so I guess that would be the absolute air pressure. I am at sea level. If I understand it right 22lb seems a bit low....do you know the correct range for turbo boost on a sprinter?
Actually if you have it set for plain BST you are getting the full boost pressure performance from your turbo charger.
I prefer using MAP as it's the same scale as the MAP sensor in the plastic box the comes up the LH side of your Charge Air Cooler. The Plastic box is simply there
to provide a good place to plug in the MAP sensor after the charge air has been cooled and just before it goes into the engine.
Hope this helps,
Roger

MAP on my 04 is above 30 psi at max boost.
MAF is in grams per second, I believe.

So, as the LHM is intermittent, I have to put some more hours on it to be completely sure, but I think the problem has been resolved. I took the vehicle in to another mechanic who was recommended to me as having a lot of sprinter experience. He noticed that the turbo actuator arm was not moving when the vehicle was being started, or when the RPM's are raised. We disconnected the arm from the turbo, and the turbo vane moved freely. So we took the actuator out, and decided to open it up and take a look at it before I sent it to be re-built. We tried to move the servo motor that drives the worm gear , and it wouldn't budge. The mechanic had heard that sometimes this can freeze up, and forcing it gently to turn one revolution can free it.

So that is what we did, and sure enough, after working it a bit, it did free up. We then put the actuator back on, connected the arm, and when we fired it up, the arm started moving again!

I have driven it for a few hours, and it has not gone into LHM mode. I am going to go out and put another couple of hours on it today, and then next week do a trip around Vancouver Island.....if it does that, then I will say it has been resolved.

The weirdest thing about this experience is that while the actuator arm was frozen, except for the occasional LHM, I was getting full turbo boost, with seemingly no problem.....it almost seems like the vane in the turbo is superfluous. My boost was going down to 1 or 1.5 lb at idle, and up to 22 lb during acceleration....I am baffled as to how this can be. I can only assume that the variation in the exhaust pressure based on the RPM's is enough to spin the turbo nicely, without the butterfly valve. I guess it must have been frozen partly open....but I still can't explain why the turbo didn't run away on me, and was able to cut out at max boost, or how the van was able to go into LHM if the vane is not moving....as far as I know, it is the actuator that the ECU would use to implement LHM.... its making my brain hurt!...if anyone has a theory, let me know! Perhaps the actuator sticking was intermittent....but it was definitely sticking twice when we looked at it, but even with it sticking, the OBD reader was still showing boost.....

So I am keeping my fingers crossed. If it turns out that this has not resolved the problem I will update the thread.

Rickster22 said:

So, as the LHM is intermittent, I have to put some more hours on it to be completely sure, but I think the problem has been resolved. I took the vehicle in to another mechanic who was recommended to me as having a lot of sprinter experience. He noticed that the turbo actuator arm was not moving when the vehicle was being started, or when the RPM's are raised. We disconnected the arm from the turbo, and the turbo vane moved freely. So we took the actuator out, and decided to open it up and take a look at it before I sent it to be re-built. We tried to move the servo motor that drives the worm gear , and it wouldn't budge. The mechanic had heard that sometimes this can freeze up, and forcing it gently to turn one revolution can free it.

So that is what we did, and sure enough, after working it a bit, it did free up. We then put the actuator back on, connected the arm, and when we fired it up, the arm started moving again!

I have driven it for a few hours, and it has not gone into LHM mode. I am going to go out and put another couple of hours on it today, and then next week do a trip around Vancouver Island.....if it does that, then I will say it has been resolved.

The weirdest thing about this experience is that while the actuator arm was frozen, except for the occasional LHM, I was getting full turbo boost, with seemingly no problem.....it almost seems like the vane in the turbo is superfluous. My boost was going down to 1 or 1.5 lb at idle, and up to 22 lb during acceleration....I am baffled as to how this can be. I can only assume that the variation in the exhaust pressure based on the RPM's is enough to spin the turbo nicely, without the butterfly valve. I guess it must have been frozen partly open....but I still can't explain why the turbo didn't run away on me, and was able to cut out at max boost, or how the van was able to go into LHM if the vane is not moving....as far as I know, it is the actuator that the ECU would use to implement LHM.... its making my brain hurt!...if anyone has a theory, let me know! Perhaps the actuator sticking was intermittent....but it was definitely sticking twice when we looked at it, but even with it sticking, the OBD reader was still showing boost.....

So I am keeping my fingers crossed. If it turns out that this has not resolved the problem I will update the thread.

Click to expand...

Specified boost is 2000 to 2200 Millibars
You state you have <22psi on acceleration,
22psi is about 1515 millibars --way down!

Star gazing and scratching my head!
Turbo variable vane area is worn and sticking.
You have a supply side pressure leak.
You have a restriction suction side
You have an atmospheric sensor reading out of whack--you are at seal level so 1000 to 1100 millibars?????
You have an outside temp sensor reading wrong.
You have an exhaust restriction, or an exhaust manifold leak.
In any case when you ask for sustained boost and you have moved outside what is required by about 25% of specified it goes limp.

Beware !
The tool you are using is most likely NOT actually live date

Dennis
Mechanic

It depends on what you are reading. 22PSI of gauge pressure is normal for peak boost. 22PSI absolute pressure is too low.

Gauge pressure is measured in reference to atmospheric pressure.
Absolute pressure is measured in refference to a vacuum.

Absolute pressure = atmospheric+gauge

Air pressure at sea level is about 14.7PSI.

Has anyone figured out the mystery? Im having the same problem with my 06... Ive replace all hoses the turbo the actuator the resonator and all sensors regarding the turbo. Mine is still going in to LHM ??? Any ideas??? Thanks so much

Well not star gazing!
It needs a scan and some data to pinpoint the issue!
Have you had it scanned ?
Here are the salient "possible" causes---like I posted above!

Specified boost is 2000 to 2200 Millibars
You state you have <22psi on acceleration,
22psi is about 1515 millibars --way down!

"Star gazing diagnostics and scratching my head"!
Turbo variable vane area is worn and sticking.
You have a supply side pressure leak.
You have a restriction suction side
You have an atmospheric sensor reading out of whack--you are at seal level so 1000 to 1100 millibars?????
You have an outside temp sensor reading wrong.
You have an exhaust restriction, or an exhaust manifold leak.
In any case when you ask for sustained boost and you have moved outside what is required by about 25% of specified it goes limp.

Beware !
The tool you are using should give live data!
Dennis

Hello all. I have a 2005 w904 sprinter 416cdi engine is 612.981
I have boost pressure lower in the middle of the day when the ambient temperature is higher than in the early morning or late evening when ambient temperature is lower.
The difference is quite noticeable.
Can you tell me if a change of boost pressure sensor also requires some sort of adaptation to the ECU.
thanks

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