Stock Turbo HELP!!!!

[duramax400ci]

ive been getting the p0299 code and ive noticed that the boost gauge doesn't go any where near the 20 or so psi that that the stock tune should do. it only goes to about 16 psi of boost. ive also noticed its like the frist time i go WOT it will push the right amount of boost but after that its just a pig and only goes to around 16 psi or lower.

So my question is what could cause this, is it the vanes?

ive took the intake off and spun the inducer wheel on the turbo to see if it was a bad bearding (i kinda figured it wasnt but just checked) and it was fine.

Any help will be appreciated

 

[yellowchevy]

Do you have any excessive smoke? If so you may have a boost leak.
Maybe you can unplug the vane position sensor and replug it in to maybe reset something?
Not sure what it is but it's the first thing I could think of.

Yellowchevy

 

[duramax400ci]

Thanks yea I'll try that

 

[duramax400ci]

any one else know any thing about this, ive noticed the light only comes on when you stop and the truck is at a idle, i clear the code and if you sit there for a min or so the light will come back on at a idle, this is super frustrating any help will be much appreciated

 

[Burn Down]

I would check the intercooler pipes & boots.

 

[duramax400ci]

yea i checked the intercooler pipes they seem to be alright, it seems like alot of guys have had this problem with there trucks to. am about to just stop the code from reporting with my efi live am so fed up with it it goes in to like a limp mode to when the truck is on and wont make more then 16 psi of boost

 

[Burn Down]

Ok when did you start getting the code? Did it just show up out of the blue, or did you change tuning or parts? This is a good read http://www.duramaxdiesels.com/forum/showthread.php?t=19299&highlight=p0299

 

[McRat]

P0299 can be caused by a LOT of things that have nothing to do with the Turbo.

A P0299 will cut your max fueling to 66% so it will drive like a *****.

A blown OEM turbo sounds like a supercharger (whine), spews oil out the tailpipe, and runs like total shiit, while pouring thick black smoke out the exhaust.

It's NOT subtle.

Do some research on 299's. I fixed them for my trucks, but I'm getting senile as to how I fixed them. IIRC, it had to do with changing the window for the Overboost/Underboost error tests.

 

[McRat]

Put stock airbox back on, clean MAF with brake cleaner, and see what happens. You might be surprised.

 

[duramax400ci]

yea i cleaned the maf sensor with maf sensor cleaner, and my air box is the stock one, i seen on a anther thread to check the bearing in the turbo by taking the turbo mouth piece off and spinning the inducer wheel when the turbo was still warm and it seemed to spin fine and kept spinning for a few seconds after even. my turbo just sounds like a stock turbo spooling up, is there any way to check if the turbo is gone for sure?!

 

[duramax400ci]

as for the tune am just running 20% more fuel on the bottom mm3 on the main injection pulse and a little more timing using joshHs timing table not any thing to big, and am running the stock desired boost tables

 

[McRat]

yea i cleaned the maf sensor with maf sensor cleaner, and my air box is the stock one, i seen on a anther thread to check the bearing in the turbo by taking the turbo mouth piece off and spinning the inducer wheel when the turbo was still warm and it seemed to spin fine and kept spinning for a few seconds after even. my turbo just sounds like a stock turbo spooling up, is there any way to check if the turbo is gone for sure?!

Turbo failures are rare on LLY's. Normally, when you pull the inlet off the charger, you'll see serious damage where the impeller hit the intake housing.

The radial play is about .030" (two matchbook covers), but WILL NOT ACTUALLY TOUCH HOUSING. These have floating bearings for better life.

In-and-out (axial) play is nearly nothing. About .005". You can feel it but it's not much.

When the vanes fail, it actually throws weird codes, not 299's. And like I said, there will be zero doubt that you have a serious mechanical issue with the engine that needs to addressed immediately. Think flat tire or missing driver's door.

 

[duramax400ci]

Thanks mcrat thats some good info

 

[8lug]

Sorry for the HIJACK but I have a similar problem, 22lbs boost even with my new PPE Boost controller... what is the best way to find boost leaks, or at least figure out if it is a boost leak?