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View Full Version : Turbo isn't working.. What am I missing??


Isla
02-01-2016, 05:24 PM
I have been through the vacuum system on my 2003 sprinter 2500 trying to track down my no boost problem.
What I know is this.. First I eliminated the possibility of boost leaks, then tested my boost sensor. The vac line leading out of the brake booster is good, the fresh air flap connection isn't leaking, the reservoir is good, the valve doesn't leak, the line between the valve and the turbo doesn't leak, and the linkage moves freely with a little vac applied.. I then checked the (outlet) or vacuum vent tube and found with some surprise that if i plugged that line with the engine running the system builds pressure and the turbo engages..
I guessed that the vacuum valve might have a one way flapper or something that was broke so i replaced the valve.. No change.. I checked the voltage coming into the valve and it reads 10.5 which doesn't seem right but maybe is for idle. When idling i can read 16" of vac on the line coming from the brake booster to the valve.
This spark any ideas out there?

jmoller99
02-01-2016, 06:49 PM
What P-Code errors is it throwing (you may need a Sprinter specific ODB2 reader to get anything I would recognize as an error)? On my 2002, MAF errors often point to a clogged EGR (when did you last clean it - I take it off and clean it every oil change.)

Isla
02-01-2016, 06:58 PM
Ive had to read and and it wasn't giving any codes related to pressure. I do have a check engine light from an unrelated issue. If the ecm is in some kind of lhm mode does it disengage the turbo?


Sent from the first city on the Mississippi.

Isla
02-01-2016, 07:00 PM
My codes were for fuel rail pressure sensor and accelerator position sensor, don't think that would make the ecm not trigger the valve would it?

Sent from the first city on the Mississippi.

NelsonSprinter
02-01-2016, 08:27 PM
. If the ecm is in some kind of lhm mode does it disengage the turbo?
Sent from the first city on the Mississippi.

Many times YES LMH disengages turbo activation,
but your vacuum reactivation is curious

jmoller99
02-01-2016, 08:42 PM
Usually, there will be some sort of P-Code if the turbo is not working. The messages never tell you what part is bad, only give you clues based on what aspect of the turbo outage it first noticed the problem at. If you are using a generic ODBII reader, it might not give you any meaningful errors at all (at least not P-Codes I am familiar with). I have a DAD unit, and as I mentioned, its not going to tell you what failed, usually only clues as to what the ECU is unhappy about (which rarely is what the problem really is).

You never answered about when you last cleaned your EGR. If you have never done anything with it, I would suspect it. The EGR and MAP sensor work together to tell your ECU what to run the Turbo at. If the EGR is stuck, or failed in some way, you will not have any turbo at all.

Green Mountain has a EGR delete program they can flash into your ECU (at about the same price as a replacement EGR for the 2002/2003). I bought a used EGR and cleaned it (so I have a working spare), but it took weeks of soaking and scraping on it to get the actuator to move smoothly on it.

The EGR on the 2002 and 2003's clog up very easily especially if you allow your Sprinter to sit and idle for long.

I had a turbo outage as a result the intake manifold temp sensor being open (a $20 part). That threw no errors, but when I monitored the intake air temp from my UltraGauge EM, I noticed that the intake temp would jump to 600 degrees F, and then the turbo would shut down (it never was 600 degrees F, but a bad temp sensor can give you bogus readings).

I always assume a split in the turbo hoses (lots of people tell me no, but then it turns out to be one). On 2004-2006 The turbo resonator is always suspect (2002/2003 don't have a turbo resonator).

After multiple Turbo outages, I bought an UltraGauge EM and watch my Boost operations like a hawk. Everything that failed never threw an error that was the real problem. However, there are clues in the P-Codes (if there are any).

Isla
02-01-2016, 11:09 PM
The last EGR cleaning, plan on it deleted, was two months ago. Cleaned it like crazy, and had it intake manifold off at the same time and cleaned the daylights out of it. It seems like maybe what's happening is the LHM mode is telling that valve to open up it's vent. I assume if I plug the vent I could be risking damaging the engine? Also i do have an ultra gauge and it reads the correct intake temp


Sent from the first city on the Mississippi.

jmoller99
02-02-2016, 03:36 AM
Is your transmission shifting gears as you drive? Even without the turbo you can get up to normal speeds (it is in no rush when this happens).

surlyoldbill
02-02-2016, 04:36 AM
Went through this twice, the most recent last year. I forgot that I went through it the first time, so made all the wrong assumptions all over again.

The EGR on the 02-03 is a replacement item, it usually lasts 100-150k with mixed driving, longer if mostly highway. It cannot be repaired. I believe that the seal on the cam arm wears out enough that a significant amount of boost pressure is lost (also where the oily mess comes from), and the sensor data does not jibe with the MAF data, and the ECU shuts the turbo off. (theory)

I know it's expensive, but I think you are due for a new EGR. If you find one for under $500, get it. There are no "made in China" generic replacements, the only one that fits and works is the Wahler (spelling?).

For a little bit more, you can get a Green Diesel Tune, which eliminates the function of the EGR. I do not know if it will work with an EGR that has already failed, but I think someone mentioned that it does.

Isla
02-02-2016, 03:01 PM
Is your transmission shifting gears as you drive? Even without the turbo you can get up to normal speeds (it is in no rush when this happens).


Transmission does shift, i've been driving it for three or four months like this, have to downshift for the smallest hill.


Sent from the first city on the Mississippi.

Isla
02-02-2016, 03:03 PM
Went through this twice, the most recent last year. I forgot that I went through it the first time, so made all the wrong assumptions all over again.

The EGR on the 02-03 is a replacement item, it usually lasts 100-150k with mixed driving, longer if mostly highway. It cannot be repaired. I believe that the seal on the cam arm wears out enough that a significant amount of boost pressure is lost (also where the oily mess comes from), and the sensor data does not jibe with the MAF data, and the ECU shuts the turbo off. (theory)

I know it's expensive, but I think you are due for a new EGR. If you find one for under $500, get it. There are no "made in China" generic replacements, the only one that fits and works is the Wahler (spelling?).

For a little bit more, you can get a Green Diesel Tune, which eliminates the function of the EGR. I do not know if it will work with an EGR that has already failed, but I think someone mentioned that it does.


I definitely have planned on deleting the EGR, was going to go with GDT, and have also looked at Malone. My buddy knows one of the big dogs at Malone and I think I can get a tune for about 250 bucks from him. I've read a lot more stuff by GDT tho. Probably just going to have to delete the EGR first and see if the turbo comes back.


Sent from the first city on the Mississippi.

surlyoldbill
02-02-2016, 05:01 PM
Definitely wouldn't hurt anything if you'd plan to get a tune, anyway. If you do get a tune and it fixes the issue, let us know. I'll be due for another EGR in 100k, and I might just get the tune instead and be done with it. That is, if I decide to keep my van for another 250k

talkinghorse43
02-02-2016, 05:08 PM
For a little bit more, you can get a Green Diesel Tune, which eliminates the function of the EGR. I do not know if it will work with an EGR that has already failed, but I think someone mentioned that it does.

I assume this tune keeps the EGR valve in the closed position? If yes, does this tune also require that the exhaust passage through the back of the head be closed off? If no, what stops nitric acid (exhaust NOX) from condensing in the dead-ended intake manifold exhaust passage and eating holes in the aluminum intake manifold?

Isla
02-03-2016, 06:54 PM
I assume this tune keeps the EGR valve in the closed position? If yes, does this tune also require that the exhaust passage through the back of the head be closed off? If no, what stops nitric acid (exhaust NOX) from condensing in the dead-ended intake manifold exhaust passage and eating holes in the aluminum intake manifold?


Not sure about all that, removing egr will increase NOX production but as far as negative effects i haven't heard.




Sent from the first city on the Mississippi.

talkinghorse43
02-04-2016, 04:24 AM
http://www.sprinter-source.com/forum/showthread.php?p=174810&highlight=intake+manifold+acid#post174810 shows what can happen if egr valve is always closed and exhaust port feeding into intake manifold isn't blocked.