Turbo Boost Pressure down?

[ciaka]

So I was working on my headlight (corner light was out). The light kept off for a while. Decided to crank out the durametric.Scanned for errors and noticed that there is a turbo charger underboost error. Never PDd turbos before. Easy? Hard on this car? Here is a pic of the actual error in Durametric:Error: P2B01 Next clip is a vid of the boost pressure I see when in accerleration from stop and from rolling 55mph, to show the boost needle vs speed/rpm. Hope someone can comment if normal....does not feel like it since I was able to see the full .8 bar on the needle from what I remember. Given the error, there is something amiss for sure.

Here are my questions:1. From the did, pic and info, do I have a problem that needs looking into?2. Where do I start now? Have of done any turbo PD, so want to understand where the areas of interest/possible issues are first.3. Provided that there is something in need of replace, what would be parts/part numbers that would be first candidates to change?4. Can someone show me what areas of interest are from a diagram, etc? Would like to know better where in car these parts are and how difficult they are to access (for example, to verify hoses, seals, tubes - which ones and where are they to verify)?Appreciate any help you can give.

UPDATE (May 26):

WTF -

I decided to go to Durametric and download/install their latest version of the Durametric SW.

My old one was v.6.2.1.2 Beta from June 2012. The latest version I installed today is v.6.3.1.7 Official Release.

After I connected the car, noticed that I was not getting the underboost error.

Cleared the error from this module. Tried again, same, no errors at all.

Cleared ALL faults from all modules.

Went for a drive and out of the community, with PSM off just floored it to see if the error will come back.

On the way back home, did same - hard acceleration.

When came home, connected again to the newest Durametric. NO FAULTS. No turbo charger fault of any kind.

So I am stumped. Could it be the sw was using wrong parameters?

Based on the vid, is it expected to see boot at this level? I am no longer 100% confident that I saw .8 bar on boost gauge, but I think it could be due to what I am observing.

Those of you in the know, please let me know your views. THANKS!!

Edited May 27, 2013 by ciaka

[JFP in PA]

Probably 65-75% of boost related issues come down to leaks in the pressurized intake system, usually hoses or hose clamps. I'd start there.

[ciaka]

Can you tell me which hoses/clamps to start with?

Are they the hoses/clamps that go away from the t-shaped plastic tube at intake? Where do they go from there?

Trying to get a good idea of the area to PD.

Also, would this have anything to do with fuses I was pulling shed doing PD of my PCM? I ended pulling momentarily all fuses in inside of driver door, including the two orange ones...just bringing this up in case it may be related.

[ciaka]

If anyone can show a diagt

Ram of area that is affected, would greatly appreciate it too.

[ciaka]

Have cleared and monitored. Got error back again but it is P0299, under boost.

I would greatly appreciate if someone could take time to explain parts in question, where they are under hood, how connected and best way to test. Again, much appreciated.

[hahnmgh63]

The Y-pipe in the front of the engine is where the throttle body bolts onto the Intake manifold. The Air travels back and forth in an S fashion from the Airboxes (air filters) to the MAF sensors (inline with the intake hoses) to the inlet of the Turbos, comes out of the Turbos under pressure now (so from here to the Y pipe is most likely where leaks occur because of the pressure) and goes into the Intercoolers (cools the hot compressed charge from the Turbos) and then travels up to the Y-pipe at the intake. So you have clamps/fittings (some with O-rings to seal) at the Turbo exit, intake and exhaust from the Intercoolers, and the small Bellows pipes you see on either side of the Y-pipe.

This is a little of a simplification but you get the idea. Check the easy ones first, clamps at the top by the Y-pipe, the Intercooler connections need to be accessed from underneath and each Wheel well. There are other places the Boost can leak (had your intake manifold off lately?)(Y-pipe cracked?), bad boost pressure sensor? Are you reading full boost on your gauge? You indicated you might. Find a deserted stretch of road, PSM off, up shift manually to 3rd gear as soon as it will let you then just floor it from the lower RPM and watch the Boost gauge climb under load (should be able to short shift to 3rd with less than 2K rpm's), should get full boost by 4K?

[bigbuzuki]

P0299 info.

P0299.pdf

Edited May 30, 2013 by bigbuzuki

[ciaka]

Have questions:

1. are the 'recirculating air valves' the diverter valves in the PDF?

2. Which items in the pics are the ones to check connections for? Trying to understand the layout here....apologies for noobness.

Should my boost pressure in cluster at WOT be pointing to .8bar in typical scenario?

Mine is pointing to .6 approx, then lowering to about .4 (I believe due to gearing/rpm range change).

Just checked some vids I have and it appears boost was at .8 at WOT, holding well into the acceleration cycle, whereas now, goes to .6 and lowers pretty soon to about .4.

Edited May 31, 2013 by ciaka

[mbagge01]

I just replaced my wastegate frequency valve (the solenoid behind the left SAI box) and I am now getting the underboost error on durametric and cannot achieve boost over 0.4bar anymore. Does someone have a diagram of which hoses connect to which end in case I may have installed it incorrectly. I am guessing that I should do a boost leak test to make sure that none of the other lines cracked or broke causing a leak when I installed it?

[mbagge01]

Does anyone have a diagram of what hoses connect to which pipe ends off the boost control solenoid

[hahnmgh63]

I can try to E-mail you a pic this weekend but I'll be out of town until Saturday morning.

[mbagge01]

hahnmgh63, don't worry about it. I figured out my problem. first off I found out the one of the hoses had ripped which was part of the problem, I a also misread PET about the connections and had some of the hoses backwards. Fixing these issues seemed to fix the problem. Thanks though.

[jamescaden]

hi there new to the place had same problem ive got an after market boost gauge as the 0.8 bar is no good as the turbo s is 27.5 psi 1.9 bar boost thats what you should be producing mine was only going to 0.4 bar so found where it was leaking and sorted it now having silicone hoses made by viper performance costly as they have gotta do 1 offs for me but as mine now peaks at 36 psi i always seem to loose boost no matter what

[Torre]

Hi,

 

Sorry for reviving such an old thread, but my issue is EXACTLY the same as OP's. I used to get 0.8 boost, now I only get 0.6 that drops to 0.4 at high RPM. I have not read my codes (if there are any) but I replaced the Diverter Valves as first aid. I also notice some oil on the bottom of the Y-piece that connects to the intake, which I probably should replace too. The diverter valve replacement did not do anything.

 

How was this case solved? So sad that people start threads and never report back how it went...:/

 

Car: 2008 CTT

Edited January 10, 2017 by Torre

[lewisweller]

21 minutes ago, Torre said:

Hi,

 

Sorry for reviving such an old thread, but my issue is EXACTLY the same as OP's. I used to get 0.8 boost, now I only get 0.6 that drops to 0.4 at high RPM. I have not read my codes (if there are any) but I replaced the Diverter Valves as first aid. I also notice some oil on the bottom of the Y-piece that connects to the intake, which I probably should replace too. The diverter valve replacement did not do anything.

 

How was this case solved? So sad that people start threads and never report back how it went...:/

I had low boost and found the 8mm ID 10mm OD vac pipe which runs along the injectors from the change over valve located at the back of the bank 2 block had two melted holes in it. After replacing that pipe and adding heat shrink wrap along its length also to protect from heat and melting I haven't had low boost since. See item number 4. 

 

Also second diagram vac pipe 4mm ID 6mm OD item number 34 which goes to each divertor valve had a split and I changed that also. 

 

Buy all vac pipes (black polypropylene I think) for a couple of dollars a meter from a hydraulic/pneumatic supplier shop and save yourselves 100's of dollars in oem parts. 

 

Very simple test for all these pipes is find the Tee of the pipe 34 which is just to the right side of the intake Y pipe in between the check valve to the right, pull it apart as per my picture attached and blow down the pipe and the open Tee end in turn, no air should be heard escaping and you should NOT be able to blow any air through, almost like it's totally shut. 

 

If this turns out not to be the issue then there are numerous other things to check off which I think I've done them all! Let us know how you get on. 

 

[Torre]

Thanks lewisweller!

 

I pulled the codes today - no fault codes at all. How easy will it be for the service to access those pipes you mentioned, how much do you need to pull stuff away? I'm trying to find a Place that has a boost leak tester to make things easier - but it seems totally impossible to find.

 

I'll report back when I know more.

[lewisweller]

5 minutes ago, Torre said:

Thanks lewisweller!

 

I pulled the codes today - no fault codes at all. How easy will it be for the service to access those pipes you mentioned, how much do you need to pull stuff away? I'm trying to find a Place that has a boost leak tester to make things easier - but it seems totally impossible to find.

 

I'll report back when I know more.

Fishing the T out from just around the surrounding components for a quick blow is not that hard, pipe to the change over valve at back  maybe nestled in or under the purge valve which I rearranged so it is above and easy to access for quick routine checks. 

 

Actually replacing the pipes is a bit more involved but dead easy. 

 

The T to change over valve pipe (8mm id) runs along the bank 2 injectors so whipping off the beauty covers and coil cover, then unplug the injectors and follow the pipe from the T back u clipping as you go until it connects to anothrr piece of pipe and then into the change over valve(has a rubber strap thing which hooks on a metal support which you can pull off to get better access). The clips/clamps are reusable so just flick them open with a small flat blade and use pliers to snap them closed on reinstallation. 

 

The vacuum tubing (4mm id) to each divertor. 

Passenger side (left hand drive) unscrew the wheel arc front only pull back and you will see the intercooler and the divertor easy pull off and feed in a new piece of pipe running through engine bay in same place as old one. 

 

The driver side is a bit harder. Crawl under neath remove bottom plastic/metal engine covers. At the end of the radiator you will see the piping to the turbo and the divertor valve with vac pipe fed down from the top area. 

 

I smoke tested the intake via the map sensor hole with a 2l bottle, two thick food bags, duck tape and a few cigarettes. And air comprrssor set at 10-15psi.