No boost

Friday1

Well-known member
Joined
Jan 26, 2003
Location
Toledo
TDI
03 Jetta Wagon 5 speed, 2012 JSW 6 speed auto, a sweet ride.
On a trip yesterday my 2003 Jetta TDI Wagon had a top speed of 68 mph. I had it scanned this morning and the results were:
Turbo overboost condition limit exceeded.
Possible culprits are:
Charge air pressure sensor.
Wastegate bypass regulator valve.
Bad turbocharger.
I would think if the turbo was bad, it wouldn't over boost.
Is the charge air pressure sensor in the ECM box with an air pressure line connected to it?
Where is the bypass regulator valve located?
Any suggestions on how to test these two units? Thanks in advance.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
On a trip yesterday my 2003 Jetta TDI Wagon had a top speed of 68 mph. I had it scanned this morning and the results were:
Turbo overboost condition limit exceeded.
Possible culprits are:
Charge air pressure sensor.
Wastegate bypass regulator valve.
Bad turbocharger.
I would think if the turbo was bad, it wouldn't over boost.
Is the charge air pressure sensor in the ECM box with an air pressure line connected to it?
Where is the bypass regulator valve located?
Any suggestions on how to test these two units? Thanks in advance.
There are a lot of things that can cause the over boost.
Clogged intake manifold, bad boost sensor (in the intercooler), sticking actuator (on the turbo) or the vanes sticking, and more.

It gets expensive guessing at what to try.

Do a search here for 'over boost' or variations. There is a good one but I do not have the link for it. :(

Rich W.
 

TreasureLife

Member
Joined
May 8, 2016
Location
Whitehouse TN
TDI
2002 Jetta TDI Wagon 5-speed
I'm having same issue

Sounds like the same issue I'm having with my 2002 TDI Jetta Wagon. I just ordered new vacuum lines, figure that's a good place to start. Someone sent me this link which has good info:
http://forums.tdiclub.com/showthread.php?t=409251
I changed out the N75 valve but that did nothing for my situation. I ordered a new check valve and vacuum hose connectors to replace them all when I get my new vacuum hose. Also got new brake booster vacuum line. Ordered stuff yesterday hope to have stuff by next weekend.
Please let me know of anything you find out and I'll do the same. Good luck!
 

fruitcakesa

Top Post Dawg
Joined
Feb 18, 2007
Location
Vermont
TDI
04 jetta 5 spd wagon
I am dealing with an over boost in my 02.
After replacing all the old vac lines, I tested the turbo actuator with mity-vac and got minimal movement from the turbo lever.
Removed the actuator and tested it out of the car and it worked fine and held vacuum.
With the actuator removed, the turbo lever still had minimal movement.
Stuck turbo vanes is my problem.
Turbo is now off the car and awaiting dismantling and cleaning.
 

Friday1

Well-known member
Joined
Jan 26, 2003
Location
Toledo
TDI
03 Jetta Wagon 5 speed, 2012 JSW 6 speed auto, a sweet ride.
Sounds like the same issue I'm having with my 2002 TDI Jetta Wagon. I just ordered new vacuum lines, figure that's a good place to start. Someone sent me this link which has good info:
http://forums.tdiclub.com/showthread.php?t=409251
I changed out the N75 valve but that did nothing for my situation. I ordered a new check valve and vacuum hose connectors to replace them all when I get my new vacuum hose. Also got new brake booster vacuum line. Ordered stuff yesterday hope to have stuff by next weekend.
Please let me know of anything you find out and I'll do the same. Good luck!
Will do, and thanks for the info. I have been scouring the forum and looking at Youtube vids. Will get under the hood tomorrow. The Youtubes are great and good info. The forum is sometimes hard to follow.
 

Friday1

Well-known member
Joined
Jan 26, 2003
Location
Toledo
TDI
03 Jetta Wagon 5 speed, 2012 JSW 6 speed auto, a sweet ride.
I am dealing with an over boost in my 02.
After replacing all the old vac lines, I tested the turbo actuator with mity-vac and got minimal movement from the turbo lever.
Removed the actuator and tested it out of the car and it worked fine and held vacuum.
With the actuator removed, the turbo lever still had minimal movement.
Stuck turbo vanes is my problem.
Turbo is now off the car and awaiting dismantling and cleaning.
Watching a Youtube today there is one showing how to free up the turbo vanes without removing the turbo using spray oven cleaner. That should work if they are not stuck too badly. I don't baby mine much but still could be stuck. Will work on it tomorrow. Thanks and I will post my solution when it is fixed. Bought this car new in 2003 and this is the first time it has given me any trouble.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Vacuum pump fitting

I ordered a new check valve and vacuum hose connectors to replace them all when I get my new vacuum hose. Also got new brake booster vacuum line. Ordered stuff yesterday hope to have stuff by next weekend.
Please let me know of anything you find out and I'll do the same. Good luck!
Before you take the brake booster line off see if the fitting is loose going into the vacuum pump. (Mine is)
Others have posted about fixing it with epoxy of peening it with a punch.
I may try the epoxy method when I do my timing belt later this year.
I was hoping to find a bad one to take apart to see if the hole could be drilled & tapped for a real pipe fitting.

Rich W.
 

Enabled

Veteran Member
Joined
Apr 23, 2013
Location
Houston, TX
TDI
2003 Jetta TDI Manual, BMW 328d SW
It took 2 oven cleaner sessions on my turbo to get rid of the overboost and limp mode, but it works.
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Without knowing which brand of oven cleaner you are referring to, some of them have flammable propellants which is held in the bubbles. If the bubbles have not all dissipated there is a chance the "fumes" will get into the intake causing runaway. If you have a couple of hours you may get the vanes loose, just don't be in a hurry to restart it. Since yours is a 5 speed, if it does anything funny stand on brake and let out clutch to stall engine after turning off key.
 

Friday1

Well-known member
Joined
Jan 26, 2003
Location
Toledo
TDI
03 Jetta Wagon 5 speed, 2012 JSW 6 speed auto, a sweet ride.
Good idea, I have had two Detroit diesels runaway on me from governor problems. They were both automatics and it is hard to stop them.
 

Enabled

Veteran Member
Joined
Apr 23, 2013
Location
Houston, TX
TDI
2003 Jetta TDI Manual, BMW 328d SW
I was spraying into the exhaust end of it, removing the downpipe and filling it up with the foam. Then hosed it down with water. Doubt it would make it into the intake too much.
 

fruitcakesa

Top Post Dawg
Joined
Feb 18, 2007
Location
Vermont
TDI
04 jetta 5 spd wagon
I'm asking a question here, because I don't know- Wouldn't it be better to clean the turbo vanes without disassembly?
I wanted to do it this way, to learn how to remove all these blasted parts when I ultimately have to do this again , and I feel I can do a much better cleaning on the bench than in the car.
 

TreasureLife

Member
Joined
May 8, 2016
Location
Whitehouse TN
TDI
2002 Jetta TDI Wagon 5-speed
Done some reading on using oven cleaner and sounds pretty convincing! Sounds like some people remove exhaust from underneath and some through the exhaust down pipe (seam like this would be easier). I read one article where a guy sprayed thru EGR and says worked great as well ( http://www.myturbodiesel.com/threads/easy-vnt-clean.17883/page-2 ). Seems like thru EGR be risky. Thoughts?
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Risky

Done some reading on using oven cleaner and sounds pretty convincing! Sounds like some people remove exhaust from underneath and some through the exhaust down pipe (seam like this would be easier). I read one article where a guy sprayed thru EGR and says worked great as well ( http://www.myturbodiesel.com/threads/easy-vnt-clean.17883/page-2 ). Seems like thru EGR be risky. Thoughts?
To much spray in the intake could cause a minor contact issue in the combustion chamber.

Just my 2 cents (US) :)
Rich W.
 

vtpsd

Veteran Member
Joined
Aug 15, 2013
Location
Vermont
TDI
03 jsw TDI, audi 90 AHU swap
Pulling the turbo is pretty easy from the bottom of these cars. I had mine out in about 45 mins and was able to get it spotless inside when totally apart. I prefer that method to the oven cleaner sprayed in the exhaust outlet method.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Not all turbos with sticking vanes are salvageable. It has been noted that the base plate the vanes attach to sometimes are warped- no amount of cleaning is going to resolve this problem.

If you know you have problems related to the turbo itself and you have lots of miles/kms on your turbo then it might just be better to replace the turbo (new ones, esp vnt15s, are pretty cheap these days- not pocket change, but one or two monthly car payments). Slap the new one on and never look back.
 

Friday1

Well-known member
Joined
Jan 26, 2003
Location
Toledo
TDI
03 Jetta Wagon 5 speed, 2012 JSW 6 speed auto, a sweet ride.
Turbo

Started troubleshooting it today. The actuator at the turbo is bad. The vanes don't move at all. The vacuum line to the turbo doesn't hold. Is there a source on this forum for a turbo, gaskets, and actuator? I guess putting some $$ in this car is a good investment. It has served me well until now.
 

aja8888

Top Post Dawg
Joined
Dec 25, 2007
Location
Texas..RETIRED 12/31/17
TDI
Out of TDI's
Started troubleshooting it today. The actuator at the turbo is bad. The vanes don't move at all. The vacuum line to the turbo doesn't hold. Is there a source on this forum for a turbo, gaskets, and actuator? I guess putting some $$ in this car is a good investment. It has served me well until now.

You have been a member here for 13 years and don't know we support vendors on the site?:confused:

Try this: http://www.idparts.com/
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
So we have multiple issues. I would disconnect the actuator rod from the turbo vnt and see if the vanes will move. This situation is covered extensively in the forum and especially in the limp mode/low power thread. Do a complete diagnose before replacing parts, some of these things are quite expensive.
Here is a partial list of vendors-
www.dieselgeek.com
cascadegerman.com
www.idparts.com
www.metalmanparts.com
VW Dealership parts-
www.1stvwparts.com
www.expressoemparts.com/
and more at
http://www.tdiclub.com/links/tdivendors.html
 

Friday1

Well-known member
Joined
Jan 26, 2003
Location
Toledo
TDI
03 Jetta Wagon 5 speed, 2012 JSW 6 speed auto, a sweet ride.
Vanes are stuck, actuator is bad, vacuum line is bad to actuator. Parts ordered from ID Parts this morning. Looks like I will be keeping this car a while. This is the first big money I have spent on it in 13 years. It has served me well so no complaints,
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Vanes are stuck, actuator is bad, vacuum line is bad to actuator. Parts ordered from ID Parts this morning. Looks like I will be keeping this car a while. This is the first big money I have spent on it in 13 years. It has served me well so no complaints,
Another TDI kept alive and our excellent vendors supported:D Expect a happy ending to this story:)
 

TreasureLife

Member
Joined
May 8, 2016
Location
Whitehouse TN
TDI
2002 Jetta TDI Wagon 5-speed
Vacuum lines replaced!

I tackled my vacuum lines today. It took me several hours but I'm crossing my fingers that my Limp Mode is cured! I've taken Gretta out and drove her hard and haven't lost boost. I ended up replacing:
  • Brake Booster hose w/check valve
  • N75
  • Check Valve
  • 5mm hose
  • 3mm hose
  • Vacuum Reservoir
I got my hose from BoostController.com i ordered turbo logic hose, I got 15' of 3mm and 10' of 5mm (had plenty left over of both). Very nice heavy duty hose! I went by this length info i found:
Per ETKA for the A4s:
3,5 X 2 (part number N 020 353 5)
350 mm from main vacuum line to a T
80 mm from a T to the N18 (black top valve)
170 mm from a T to a small check valve
45 mm from a T to the N75 (white top valve)
530 mm from a T to the vacuum canister (damper)
1000 mm from turbo to a connecting pipe
60 mm from a T to a T
180 mm from a T to N239 (change over valve)
120 mm from N239 to vacuum actuator
5 X 3 (part number N 020 282 1)
360 mm from N18 to EGR valve
50 mm from N75 to connecting pipe (going to turbo)
320 mm from N75 to fresh air line T
80 mm from N18 to fresh air line T
300 mm from air box to fresh air line T
T pieces are part number 113 201 943 B
small vacuum check valve is 046 905 291 A
connecting pipe is 06A 133 382 K
And routed it according to this diagram:https://farm9.staticflickr.com/8722/16872254906_166acf578c_b.jpg
Hope this solves my problem. I'll keep driving it hard and see if it's really fixed!
 

Friday1

Well-known member
Joined
Jan 26, 2003
Location
Toledo
TDI
03 Jetta Wagon 5 speed, 2012 JSW 6 speed auto, a sweet ride.
Turbo pre lube

Is there a fuse I can remove to keep the motor from starting, or a preferred method so can make sure the turbo has oil on first start? Thanks in advance.
 

TreasureLife

Member
Joined
May 8, 2016
Location
Whitehouse TN
TDI
2002 Jetta TDI Wagon 5-speed
Quick update: after all i replaced last time still getting over-boast codes and limp mode. Not sure what to do still drives great 99% of the time. Guessing need to pull turbo off, rebuild

frustrating
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
What is your actual code? There are other things that can cause this, I'd rule them out before you go at the turbo, unless you know it is bad.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Vanes are stuck, actuator is bad, vacuum line is bad to actuator. Parts ordered from ID Parts this morning. Looks like I will be keeping this car a while. This is the first big money I have spent on it in 13 years. It has served me well so no complaints,
Same with mine. Only alternator & tensioner problems.
Bought mine new.
I always had good luck with VW's going back to air cooled days.
Couldn't begin to guess how many bugs I had back then not to mention the others. :D
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Quick update: after all i replaced last time still getting over-boast codes and limp mode. Not sure what to do still drives great 99% of the time. Guessing need to pull turbo off, rebuild

frustrating
Sorry if I missed it, but have you tried adjusting you actuator rod?

I believe that normally you can detect if vanes are sticking -there's a lull in rpm pick up- in which case sometimes one can exercise this out (I did on the wife's car, though it took a couple of years of limited hands-on thrashing to free up- was pretty subtle sticking).
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
Some have tried running the engine in a lower gear at highway speed to put more heat into the turbo vanes to possibly free them up.
 
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