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Discussion Starter · #1 ·
Working on a friend's Passat wagon, and he wants me to replace the turbo to fix the code. It 'may' be the turbo, but I want to make sure before throwing useless parts at it..
I've read on here many times that it could be the turbo, a boost leak, the MAF, the EGR, N75, the wastegate, etc. I've vacuum and boost-tested the wastegate, and it seems fine, moves freely, and will hold boost/vacuum.
The car has 393K on it and I'm unsure of the previous history, other than it was a one-owner before he bought it a couple years ago. It's been sitting now for almost a year, as it was going in to limp mode constantly.
I ran VCDS and pulled the P0299 and P0101. I saved the file, cleared the codes, but they came right back, in short order.. As he stated was pretty easy to get the codes to come back; I was able to quickly able to replicate the issue..

I went to remove the intercooler 90* from the throttle flapper. As I reached under the pipe to feel for the clip release, and my fingers were covered in wet oil..
I pulled it off, and there were no holes in the L-hose.

So, the S-hose has a fat 2" long split! Additionally, the lower part of the S-hose didn't look fully seated into the cross-over tube. I replaced this with one from ECS Tuning, plus all the 3 & 5mm vacuum lines, as well as the N75.

I ended up with a Vaico from ECS for about $200. Also replaced the N75, and all the vac lines. Did all that, as well as replace the stupid clip on the turbo outlet-to-S hose.. Got the clip from Jim Ellis VW. Put it all together, replaced the fuel filter, while I was waiting on parts.

Drove it around for about 20 minutes, no issues. Ran down the interstate for about 5 miles, no issues.. Crossed under to get back on the interstate and head home, turned onto the on-ramp, and Emissions! light popped on.. Cycled ignition to clear LIMP mode, about 1/2 way up the ram, it popped up again and went back to limp mode. I eased it home, VCDS showed P0299 again. 2130 requested, 1700-ish actual..
Unless the turbo has taken a crap, I don't know what the problem is.
I'm open to suggestions, for sure.. I'm kinda guessing/leaning to a turbo failure? I mean, AFAIK, it's OEM with 393k miles on it.

I verified ALL my connections for charge-air. All o-rings looked perfect, all snap-connections were solid. The ground wire wasn't touching the S-hose, so no issue there; the original one just split.

o capped off the IC plumbing between the 90* and the turbo inlet.. 8psi + smoke test showed no leaks.. VGT actuator sweeps up and down smoothly under vacuum, starting to move at around 3in/vac, up to about 16-ish" when it stops moving. holds vacuum for 5 mins fine, no loss. I can move the plunger up/down on the actuator with no noticeable sticking, etc.

Would this point to a possible faulty turbocharger for these 0299/0101 codes?


TLDR: 2 codes. Replaced ripped S hose, N75 solenoid, all vacuum lines. verified VGT vac. actuator operation and ability to hold vac. Smoke tested under 8psi between turbo inlet and intake manifold intercooler connection with no visible leaks.

Having not a ton of VW diesel knowledge (I work on Cummins diesels) and their quirkiness, what's a good avenue to go down, before we start throwing a bunch of unneeded parts at it?
Thanks in advance, guys!
 

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Discussion Starter · #2 ·
EXAMPLE 1

YOu can see where the actual boost (yellow) was following the specified boost (green), then just kinda fell off at a gear change, then it's 2nd climb (yellow) and fall, then third climb, car dropped into LIMPO mode. and EMISSIONS WORKSHOP triggered. RED is rpm. I cycled ignition, and continued on, clearing the limp mode..


EXAMPLE 2


EXAMPLE 3

Example 3, the first call for boost (in a parking lot) was fine. the 2nd call for boost (middle of graph) was pulling out onto the road. Boost (actual) never made it to specified, and Limp Mode was triggered.

In VCDS, I went into Engine, into Tests, and tested N75 connected to VNT actuator (VNTA) and it worked as expected, with the actuator arm moving about a 1/2" stroke each cycle. Retested with the VNTA disconnected, and a VAC gauge connected to the VNTA port of the N75, and saw cycles of 22inHg - 0inHg, as expected.

So, this leads me to believe that it is, indeed, a turbo issue, since no leaks in charge air tubes was detected in smoke/pressure tests..
Your thoughts?
 

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See if a moderator can move you to the right forum. You're in mk3 and you should get better results in b5.5.

If it has an EGR/ cooler check the pipes for leaks. This leak on my car, a BEW jetta fooled the smoke test and created much consternation on my mechanic.

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See if a moderator can move you to the right forum. You're in mk3 and you should get better results in b5.5.
If the new mod does his job right.

VAG Error Code: 16683/15343/15343/14914/11226/12896/7384/5171/5671/000665

EOBD II Error Code: P0299

Fault Location:
Boost Pressure Regulation - Control Range Not Reached/Low Boost

Possible Cause:
Malfunction Indicator Lamp (MIL)(K83) active.
Reduced Power Output.
Limp Mode.
Limp mode: What is it, what are the causes, and how to fix it for the Audi and VW TDI diesel turbo

Hoses/Pipes incorrectly connected, disconnected or leaking.
Charger Pressure Control defective.
Turbocharger faulty.
Diverter Valve faulty.

Possible Solutions:
Check Hoses/Pipes to/between Components.
Check/Clean/Replace Charge Pressure Control.
Check Turbocharger.
Check Diverter Valve.

Special Notes:
If the Turbocharger is faulty due to mechanical/internal problems or the exhaust system is restricted (typically the Catalyst) this fault may be the end result.

Gasoline:
When found in 2.0l TFSI:
Check Boost Pressure Control Valve (N249) (Turbocharger Recirculating Valve) for cracked rubber diaphragm. A new/optimized Valve is available under Part # 06H-145-710-D (or newer).
Rest of World (RoW) vehicles see: Technical Product Information (TPI) 2016331 for details.
North American Region (NAR) vehicles see: Technical Service Bulletin (TSB) 01-07-70 or 2013392 for details.
When stored in conjunction with misfire codes and/or fuel trim faults see the notes associated with the following faults regarding Positive Crankcase Ventilation (PCV) failure: Crankcase Breather Valve
When found in Audi A4/S4/RS4/Cabriolet (8K): 2.0l (CAEB):
See Technical Product Information (TPI) 2031245/6 - turbocharger excessive waste-gate play.

Diesel:
When found in VW Golf/Jetta (1K): 2.0l CR-TDI (CBEA/CJAA):
Verify the mechanical part of the Exhaust Valve Control Module (J883) is not seized or binding.
When found in the 1.9 L TDI-PD (BLS):
Check vacuum supply from the vacuum reservoir located in the valve cover for leaks. Using a vacuum gauge, wiggle the valve cover and hose connections to check for a leak. The following photo was submitted from a customer working on a 2010 VW Caddy (2K chassis) with this vacuum reservoir problem.

16683 / P0299 / 000665 - Boost Pressure Regulation: Control Range Not Reached

Google this YouTube link

Does Your VW/Audi 2.0t TSI Have A Bad Turbo

Google this YouTube link


VAG Error Code: 16485/4794/7329/7330/5667/4795/000257

EOBD II Error Code: P0101

Fault Location:
Mass Air Flow (MAF) Sensor (G70) - Circuit Range/Performance Problem/Implausible Signal - Intermittent Not Confirmed - Tested Since Nlemory Clear

Possible Cause:
Malfunction Indicator Lamp (MIL)(K83) active.
Loss of Power.
Erratic Idle.

Wiring/Connector(s).
Air Leak(s) after Mass Air Flow (MAF) Sensor (G70).
Excessive restrictions in the Intake/Exhaust System.
Dirty air filter, clogged snow screen, clogged CAT.
Mass Air Flow (MAF) Sensor (G70) faulty,
Ground Spots corroded or Paint Residue.

Possible Solutions:
Check/Replace all faulty Wiring/Connector(s).
Check Intake Air Filter.
Check Mass Air Flow (MAF) Sensor (G70).
Check Earth Points.
Read Measuring Value Blocks (MVB).
Mass air flow vs upper threshold model < 60 - 800 kg/h.
Lower threshold model < 0 - 400 kg/h.
Load calculation > 18%.
Fuel system < -17%.

Special Notes:
In MY 1995-2002 (?) in Europe at VW diesel cars Mass Air Flow (MAF) Sensor (G70) had the bad reputation of slowly losing his performance, causing loss of power. It's not a matter of defective or breaking down, but it is filthy / dirty (not easy to clean). You can check functionality by making a log in [01-engine], [Measuring Value Blocks (MVB) - 08], group 003 (3rd gear, full throttle, from 1700-4000rpm).
It is not uncommon for a TDI to set Implausible Signal Mass Air Flow Sensor (G70) faults when the engine performance is reduced due to a mechanical problem. These mechanical problems may include, but are not limited to:
Faulty electric fuel pump or Restricted fuel filter. See the Fuel Pump Basic Settings for PD, PPD, and CR TDI Engines page for Basic Settings tips after replacement.
Excessive restrictions in the intake/exhaust system.
Internal camshaft/valve/lifter problems.

Tech Notes:
Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner. Reset code and drive vehicle. If the code comes back, it may be necessary to replaced the mass air flow sensor.

When is the code detected?:
A high voltage from the sensor is sent to Engine Control Module (ECM) under light load driving condition.
A low voltage from the sensor is sent to Engine Control Module (ECM).

Description:
The Mass Air Flow (MAF) Sensor (G70) is placed in the stream of intake air. It measures the intake flow rate by measuring a part of the entire intake flow. It consists of a hot film that is supplied with electric current from the Engine Control Module (ECM).

The temperature of the hot film is controlled by the Engine Control Module (ECM) a certain amount. The heat generated by the hot film is reduced as the intake air flows around it. The more air, the greater the heat loss. Therefore, the Engine Control Module (ECM) must supply more electric current to maintain the temperature of the hot film as air flow increases. The Engine Control Module (ECM) detects the air flow by means of this current change.

As taken from my new Free EOBD II Error Codes software
 

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Discussion Starter · #6 ·
I sent a request to have it moved to proper place..
Keith, thanks for your info.
But as you can see, I've went through most all the tests/checks you've posted. I've read through the same info on ross-tech, etc. and beat YT to death for info..

I'm surprised this forum doesn't have more active traffic than it seems to have..
 

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VW Jetta TDI Mk5 2005.5 BRM
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In case you haven't seen the fixing limp mode guide, might provide some helpful troubleshooting steps.

You mentioned vacuum/boost-testing the waste-gate, have you done the same for the VNT actuator? Have you done a smoke test? I've heard of stuck turbo vanes causing similar issues but I haven't had experience with that myself. Recently had boost leak issues that I wasn't able to identify until getting a smoke test done.
 

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In case you haven't seen the fixing limp mode guide, might provide some helpful troubleshooting steps.
Another good link restored, what about the rest?

I have loads of TDI Wiki threads the only difference is /d2/ if I added /d2/ to them they don't show.

e.g.

New link

https://www.myturbodiesel.com/d2/1000q/

Limp mode: What is it, what are the causes, and how to fix it for the Audi and VW TDI diesel turbo

old link


Limp mode: What is it, what are the causes, and how to fix it for the Audi and VW TDI diesel turbo
 

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You need to disconnect the actuator from the turbo and move the lever with your hand.
In the first picture of the link you can see a worn actuator lever. This lever, and the ring it moves, gets more worn and tends to stick open. This causes an overboost and then it's followed by limp mode. Replacing the actuator and the N75 will do nothing for this. It requires a new turbo if it stays open at max boost.


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Discussion Starter · #11 ·
You need to disconnect the actuator from the turbo and move the lever with your hand.
In the first picture of the link you can see a worn actuator lever. This lever, and the ring it moves, gets more worn and tends to stick open. This causes an overboost and then it's followed by limp mode. Replacing the actuator and the N75 will do nothing for this. It requires a new turbo if it stays open at max boost.


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Overboost is NOT the issue causing this particular limp mode. It's actually the opposite, as stated earlier in this thread.
The specified and actual boost levels are in alignment, for the first 20 or so minutes of driving. Then, the actual will climb to specified, then slowly start dropping until limp mode is reached, due to LOW boost... If you take a quick look at the images above, you'll see that overboost is not the problem.
I can cycle the ignition, and this process repeats It'll boost normally for a few pulls, then boost and taper off to limp, afterward...
 

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I get that, I was trying to point out that you need to physically move it by hand.
Try looking at the boost sensor also. The ecu compares three readings. Also try logging the MAF actual to requested, it might tell you more.
Lastly, you might want to inspect the intercooler...

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Discussion Starter · #14 ·
I've examined the IC, nothing that I can see. no boost leaks or smoke leaks when pressure/smoke testing the IC and all plumbing. I've moved the actuator lever by hand (albiet not easy with it still connected to actuator) and I did not notice any sticking or whatnot. I can try to remove the clip (and not lose it in the process) and try moving the lever again..

I'll also graph the MAF actual/req. You say 'boost sensor'.. you referring to the MAP sensor?
 

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Yes, map sensor.
Low boost should correspond with reduced air intake. However, if intake is correct map is bad. It's uncommon for the map sensor to be bad, yet it's possible. So my theory is to pull the clip on the actuator and ensure easy complete movement. Check boost requested versus actual along side MAF actual versus requested.
There's a great possibility that the turbo is bad, especially if you don't know it's been replaced.
Overboost and underboost are related in causation. Sticky veins and worn parts are the most likely culprits. So take them in order and don't skip steps, we always chase our tails otherwise.

I would almost bet that there moment you get the clip off and move the actuator lever you'll feel what's wrong.

Another place it occurs that needs checked are the intake and exhaust torque's. Just to be sure they aren't leaking causing the issue. I had my intake come loose before, it can be difficult to torque on the vehicle.

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Discussion Starter · #17 ·
OK..

  • Valve cover gasket replaced
  • Turbo disassembled, checked end play and wobble: Felt perfect
  • Cleaned Turbo completely - including the VNT section Now it moves like butter. no bent vanes, no sloppiness where the actuator arm moves the ring..
  • New Downpipe gasket, oil drain gasket, EGR Cooler gaskets
  • New hardware (studs, nuts, etc)
  • Checked/cleaned MAF and MAP
  • Checked/cleaned intercooler pipes
  • Removed, cleaned and reinstalled intake manifold, including new gasket
  • WGA tested; holds vacuum as tested
  • Vacuum canister under turbo holds vacuum as tested
Reassembled everything, took it for a drive. Stayed in town, driving around, seemed fine. Spent about 30-40 mins doing this..
Decided now's the time, let's hop on the bypass and get some speed...
Turned onto the on-ramp, accelerated to about 35-40, BEEEEP.. Limp mode.
Went to next exit and pulled over, whipped out the VCDS. P0299.. Requested: 2364mb, 1754.4mb actual.

N75 has been replaced
EGR was cleaned
All vacuum lines replaced
Vacuum check valve replaced
Air Filter replaced

I'm out of guesses, at this point.. Short of buying an EGR blockoff ant 'testing' to see if the EGR is not seating properly, I don't know what else to do..

PLEASE, throw me some ideas, if you have any more.. I'm at my wits end with this car now.
Thanks.
 

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Hi, feel your pain. Had a similar issue a while back. Is this a Garrett turbo?

You’ve already done everything I can think of and so it is time to remove the turbo.
If the fasteners dont fight fight you this is a 1 to 2 hr job.
Be careful with the oil lines.

Now pull apart the turbo and clean the vanes and the housing of carbon. Theres youtube vids but its all straightforward.
Worked for me after I stubbornly did everything else while refusing to re & re the turbo
 

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Discussion Starter · #20 ·
And edit…my bad. You’ve decarboned already.
Ok so is it a Garrett or a Mahle turbo?
I think Garrett? Crap, I can't remember. I remember a green metal tag.. hah
GT1749VA, that's all I remember, honestly.
I pulled the valve cover back off..Closer inspection showed well-worn cam lobes. I couldn't really see the lifters, but the lobes are pretty flat/ridged.. I can post pics later..
Someone told me a worn cam and/or lifters will cause it, too.. so that's why I looked.. IDK.
 
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