Looking for a Guru!

Hi,

I am pretty new to the forums and a first time owner of a TDI. I have a 2003 Jetta TDI. I took a trip to West Virginia this past weekend and on the way home the car went into limp mode and had an overboost code (see below).

I have been noticing a seeming intermittent lack of power since I bought it and am leaning toward a gummed up turbo. The previous owner told me he shifted around 2500 RPM and from reading this forum it seems babying the car is bad for clogging up the vane mechanism.

I have a Ross Tech cable and VCDS on my laptop, I just don't have all the knowledge or tools to properly diagnose this and I would rather not be a parts changer.

I am in the Exton PA area if any gurus would be able to help me out. I have no problem buying whatever parts are needed and compensating for time with money or a mutually agreed upon payment.

Sunday,19,May,2019,18:24:42:11195
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 8 x64
VCDS Version: 18.9.1.0 (x64) HEX-V2 CB: 0.4437.4
Data version: 20190114 DS296.0
www.Ross-Tech.com


VIN: 3VWSP69M13M058940 License Plate: KXY8017
Mileage: 379975 Repair Order:



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Address 01: Engine Labels: 038-906-012-AGR.clb
Control Module Part Number: 038 906 012 GN
Component and/or Version: 1,9l R4 EDC G040SG 4308
Software Coding: 00002
Work Shop Code: WSC 00066
Additional Info: 3VWSP69M13M058940 VWZ7Z0B5774561
VCID: 629DAB06ED5D0AA7E89-4B3C
1 Fault Found:

16618 - Boost Pressure Regulation
P0234 - 35-00 - Limit Exceeded (Overboost Condition)

Readiness: 0 0 0 0 0

Mair's Continental Motors in Reading may be able to help. I believe they do a fair amount of work on TDIs.

Odds are you either have a failing turbo actuator or stuck vanes in the turbo. Shifting at 2500 RPM isn't super gentle, so I'm thinking the actuator is more likely. You could take the car out and drive it hard (4th gear to redline with the accelerator floored) to build up some heat in the turbo and clean out the carbon. May or may not help.

IndigoBlueWagon said:

Mair's Continental Motors in Reading may be able to help. I believe they do a fair amount of work on TDIs.

Odds are you either have a failing turbo actuator or stuck vanes in the turbo. Shifting at 2500 RPM isn't super gentle, so I'm thinking the actuator is more likely. You could take the car out and drive it hard (4th gear to redline with the accelerator floored) to build up some heat in the turbo and clean out the carbon. May or may not help.

Click to expand...

I'm looking for someone that can help me do it myself rather than paying a shop to do it.

overboost is usually sticking boost solenoid (n75) or sticky vanes in the turbo. Here is a video on diagnosis.

https://youtu.be/02KJxNnYiZk

That is a very well made tutorial. I wasn’t aware those graphs could be saved in paint. That’s a self less use of your time, you’re all right.

CoolAirVw said:

overboost is usually sticking boost solenoid (n75) or sticky vanes in the turbo. Here is a video on diagnosis.

https://youtu.be/02KJxNnYiZk

Click to expand...

I'm bracing for it to be sticky vanes because intermittently it seems to fall on its face and not trigger the overboost code.

I have been leaning toward replacing the turbo anyway as I get a puff of smoke at start up indicative of possible seal failure and I would rather not have the possibility of a run away engine.

On that note, do you have any thoughts on a replacement cartridge like this: https://shop.advanceautoparts.com/p...n/11584185-P?navigationPath=L1*14932|L2*14988

Would a cartridge replacement take care of the seal issue? Are there any other concerns if I go that route? I figure if I have to take the turbo off anyway I might as well do it right the first time, even if it does cost me a little bit.

'lectricjeff said:

On that note, do you have any thoughts on a replacement cartridge like this: https://shop.advanceautoparts.com/p...n/11584185-P?navigationPath=L1*14932|L2*14988

Click to expand...

Thoughts?

Don't waste your money!

Unless you can get a part from the original manufacturer and I do not believe they are available.

'lectricjeff said:

I'm bracing for it to be sticky vanes because intermittently it seems to fall on its face and not trigger the overboost code.
I have been leaning toward replacing the turbo anyway as I get a puff of smoke at start up indicative of possible seal failure and I would rather not have the possibility of a run away engine.
On that note, do you have any thoughts on a replacement cartridge like this: https://shop.advanceautoparts.com/p...n/11584185-P?navigationPath=L1*14932|L2*14988
Would a cartridge replacement take care of the seal issue? Are there any other concerns if I go that route? I figure if I have to take the turbo off anyway I might as well do it right the first time, even if it does cost me a little bit.

Click to expand...

Avoid that Chinese cartridge like the plague. It will not last very long and may well cause your engine to run away at first startup. If it does fail and destroy your engine, the only thing Advance Auto Parts will do for you is cheerfully give you another Chinese garbage cartridge.

Soak the actuator arm on the turbo with penetration oil and work it up and down should loosen it. Should have around an inch of play. Then go out n blow the carbon out it should definitely help

Just got finished replacing the vacuum lines. I doubt that it is going to improve the issue let alone fix it but for less than an hours time and $30 figured I'd give it a shot.

The N75 seems to be working fine and the actuator does hold a vacuum >25 inmg. I can see the actuator moving when I cycle the N75 in VCDS but I can't measure how far it is physically moving until I get it off the ground and get under it.

I'm still fairly certain the issue is dirty vanes and I'm going to have to pull the unit, which if I do that I'm replacing it due to the oil useage.

Ok, so I haven't gotten the car of the ground yet to check the actuator arm movement. I did do some 4th/5th gear WOT runs that I logged. I logged RPM, MAF Specified and Actual, and Boost Specified and Actual. In one I also logged the N75 rating. Every time I logged it went into limp mode. I marked the 4th gear shift and the 5th gear shift. The second log you can ignore the first mark as I had to slow down for traffic. I was not able to get to redline in any run I took, once I get to around 4k RPM it just doesn't want to go any more.

Since I am not familiar with what these results should be, but being a controls electrician, it looks like the MAF is fine as well as the turbo unit itself as the values seem to be lining up pretty well until the overboost condition.

Tomorrow the plan is to check the snow screen, and cut it out if still there, just for ****s and giggles, check the arm movement and make sure that is correct, if it is, then I will swap the N75 with the NXX for the EGR to rule out the N75 since this has an EGR delete.

Oh, I also noticed that when I park the front of the car going downhill the smoke cloud is much bigger and lasts until I get it off the incline. Could this mean the turbo isn't where my oil is going out of, maybe valve guides and seals are bad?

PS is there a how to for attaching excel files so you guys can look at the logs?

Are you losing any significant amount of oil?

Ross Tech lists the following most likely causes :

Possible Causes
Hoses incorrectly connected, disconnected, blocked or leaking
Boost Pressure Control Valve (N75) faulty
Boost Pressure Sensor (G31) faulty
Turbo Charger stuck/faulty

Sounds like you have ruled out all except the G31 Sensor
It will mostly likely be the G31 , if not , then the MAF

Would leave the snow screen if it can be cleaned and remains in suitable condition. Dawn dish liquid and toothbrush.
Not for snow, but for rodent prevention.
Have fabricated new ones from nylon mesh/screen a couple times on customer cars that had been removed.
Rodents seem fond of TDI airboxes in my area.

Your oil consumption is probably not turbo related.
Do a Cold/Warm/Hot "Blow-By" check on the engine by removing oil fill cap with engine running.
Make sure you can read dipstick properly - not overfilled.
Paint the lower section white or silver if need be.

MAF's can be funky demons sometimes - would start with G31 though.

I'll throw this in for what it may be worth..

I gave my 2000 Jetta to my son. Engine and Turbo are OE. It has always had good boost. I never did WOTs, however, I did practice taking the RPMs up to 3200 to 3600 in the first three gears four or five times per tank of fuel..... Boost peak is what you are looking for ... WOT doesn't always give that! If you have a Boost Gauge you will understand what I'm saying...

Now, fast forward to January of this year, I began making my 2003 Jetta with a 2001 engine in it the daily driver. The 01 Engine was in my brother's car. It was always sluggish and was still sluggish in the 03 (I purchased it from my brother).. Well, today, about 6 months of using it as a daily driver, the Turbo is finally functioning much better, almost on par with the 2000 Jetta. Other than an IP reseal, changing oil, filters and transmission oil, I did nothing to make it perform better. However, I have done the RPM thingy in the first three gears each time I'm out in it. I think this has "exercised" the VNT mechanism across it's full travel. (I did check the timing, slightly above the spot on line..)

JB05 said:

Are you losing any significant amount of oil?

Click to expand...

Roughly 3/4 to a quart of oil since I changed at around 375k miles. I'm about 500 miles shy of my 10k change.

Baron VonZeppelin said:

Your oil consumption is probably not turbo related.
Do a Cold/Warm/Hot "Blow-By" check on the engine by removing oil fill cap with engine running.
Make sure you can read dipstick properly - not overfilled.
Paint the lower section white or silver if need be.

MAF's can be funky demons sometimes - would start with G31 though.

Click to expand...

What am I looking for with the blow by test, just the amount of air I can see exiting the oil fill?

AndyBees said:

I'll throw this in for what it may be worth..

I gave my 2000 Jetta to my son. Engine and Turbo are OE. It has always had good boost. I never did WOTs, however, I did practice taking the RPMs up to 3200 to 3600 in the first three gears four or five times per tank of fuel..... Boost peak is what you are looking for ... WOT doesn't always give that! If you have a Boost Gauge you will understand what I'm saying...

Now, fast forward to January of this year, I began making my 2003 Jetta with a 2001 engine in it the daily driver. The 01 Engine was in my brother's car. It was always sluggish and was still sluggish in the 03 (I purchased it from my brother).. Well, today, about 6 months of using it as a daily driver, the Turbo is finally functioning much better, almost on par with the 2000 Jetta. Other than an IP reseal, changing oil, filters and transmission oil, I did nothing to make it perform better. However, I have done the RPM thingy in the first three gears each time I'm out in it. I think this has "exercised" the VNT mechanism across it's full travel. (I did check the timing, slightly above the spot on line..)

Click to expand...

I routinely take it to 3200 to above 4000 based on advice to keep the mechanism clean from others here. I don't do WOT too often so I don't usually get limp mode but I have gotten limp mode in both WOT runs I did yesterday.

'lectricjeff said:

Roughly 3/4 to a quart of oil since I changed at around 375k miles. I'm about 500 miles shy of my 10k change.


What am I looking for with the blow by test, just the amount of air I can see exiting the oil fill?

Click to expand...

A quart in 10k miles is not really "bad" at all -especially with 380'ish on the odometer.

The more oily-haze smoke you have coming out of the oil fill hole - indicates the amount of wear in the cylinders and/or piston rings.
Some is acceptable.
If its gushing like a freight train - not good.
Check at cold-warm-hot operating temps.

Yours is probably more related to valve stem seals and/or valve guide wear.
Just going by your consumption in 10k miles.

Just to clarify -
Did you mean to say 5,000 miles shy of next oil change ?
Or is 500 miles shy - the correct number.

You stated 375k oil change, VagCom shows mileage right at 380k

Baron VonZeppelin said:

Just to clarify -
Did you mean to say 5,000 miles shy of next oil change ?
Or is 500 miles shy - the correct number.
You stated 375k oil change, VagCom shows mileage right at 380k

Click to expand...

500 is correct. The 380k was weeks ago when I started on this. I'm presently sitting at 384700ish.

It really only seems to blow the white blue smoke at start up. I originally figured turbo since I don't know the age of the turbo. Not sure if the head was ever rebuilt either.

You should upload your VCDS logs to the Malone Tuning site and then put the URLs to the graphs created on here. The turbo actuator is cheap on Amazon. I would swap it out. If you do have to replace the turbo, throw a VNT17 in there. Much faster.

'jeff, check out Dutch Auto Parts for a replacement turbo. Franz is very well respected in these forums and nobody beats his prices. Use this link and look at post #3:
https://forums.tdiclub.com/showthread.php?t=434593

Rrusse11, lives near the Dutch colonies and has a great shop he uses that is local to him, I am sure if you ask him he will give you their 411.

Links for the logs:

Run 1: https://log.malonetuning.com/chart/...YEMOCwol5d23DmyrDni3CjCl9AVTDlcONw7DCkwAAAA==

Run 2: https://log.malonetuning.com/chart/...gwpgQw4LCiXl3bcObKsOeLcKMKX0BVMOVw43DsMKTAAAA

Guessing you've seen this, but lists other possibles.
You may want to get underneath, you can chack the vanes by had operating the actuator. Also check down there for any loose picking.
1 quart oil in 9,000 miles is good.

BobnOH said:

Guessing you've seen this, but lists other possibles.
You may want to get underneath, you can chack the vanes by had operating the actuator. Also check down there for any loose picking.
1 quart oil in 9,000 miles is good.

Click to expand...

Yeah I've seen that. After looking at the graphs and seeing the actual boost pressure with the N75 duty cycle damn near overlaying each other I think the turbo vanes are fine. I'm leaning toward the actuator being misadjusted and travelling further than it should. Or the MAF since it is really difficult to actually diagnose that by anything other than replacing it.

I will jack it up, hopefully this weekend and check the adjustment of the actuator.

Put a vacuum pump on the actuator to see if it holds vacuum.

JB05 said:

Put a vacuum pump on the actuator to see if it holds vacuum.

Click to expand...

Already did that, it holds vacuum.