www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You




Go Back   TDIClub Forums > TDI Model Specific Discussions Areas > VW MKIV-A4 TDIs (VE and PD)

VW MKIV-A4 TDIs (VE and PD) This is a general discussion about A4/MkIV Jetta (99.5-~2005), Golf(99.5-2006), and New Beetle(98-2006). Both VE and PD engines are covered here.

Reply
 
Thread Tools
Old May 18th, 2018, 09:01   #1
jeffbrom
Newbie
 
Join Date: Feb 2007
Location: Ohio
Default Loss of turbo power around 3000-3400rpm

Hello All,
I have been trying to remedy this problem for some time. This is on a 2003 MKIV TDI with the auto transmission. If I accelerate at a brisk rate, such as 3/4 or full throttle, the turbo boost and acceleration is good till the rpms hit about 3000-3400 then power drops off, rpms drop off, and usually goes into limp mode with no boost at all and a CEL. Restart engine and repeat. If I let off the throttle, and vary the throttle position I can avoid the limp mode most times, but of course I am not accelerating like I should be!
I have tested and replaced the MAF with a known good from my 02 and still have the problem. I have checked and replaced the N-75 turbo boost solenoid valve, still have the problem. I had first tried NEW ones of both the above, but was unsure if they were defective, so did the swap with my known good ones to be sure.
I have a VAG-COM and have run the test for the turbo boost vacuum actuator and the linkage arm moves back and forth to the extent I would expect is full range, about 3/4-1". I have also disconnected the vacuum hose and used a handi-vac type hand pump and it moved the same.
Does anyone know of more tests I could perform to figure this out?
The car runs good otherwise, and doesn't burn any engine oil.
Some of my thoughts are that it could be carbon build-up cutting down air flow in the turbo? Maybe choked airflow in the intercooler area?
The engine in this car was swapped out with a good lower mileage engine before I purchased it 4 years ago, by a diesel mechanic who also did work on VW's, and I believe he said the intake was in good shape/clean before it was put in. The timing belt kit was done at that time also.
Any suggestions are appreciated, THANKS!
Jeff
jeffbrom is offline   Reply With Quote
Old May 18th, 2018, 10:43   #2
super1
Veteran Member
 
Join Date: Apr 2010
Location: NY
TDI(s): none
Default Loss of turbo power around 3000-3400rpm

Quote:
Originally Posted by jeffbrom View Post
Hello All,
I have been trying to remedy this problem for some time. This is on a 2003 MKIV TDI with the auto transmission. If I accelerate at a brisk rate, such as 3/4 or full throttle, the turbo boost and acceleration is good till the rpms hit about 3000-3400 then power drops off, rpms drop off, and usually goes into limp mode with no boost at all and a CEL. Restart engine and repeat. If I let off the throttle, and vary the throttle position I can avoid the limp mode most times, but of course I am not accelerating like I should be!
I have tested and replaced the MAF with a known good from my 02 and still have the problem. I have checked and replaced the N-75 turbo boost solenoid valve, still have the problem. I had first tried NEW ones of both the above, but was unsure if they were defective, so did the swap with my known good ones to be sure.
I have a VAG-COM and have run the test for the turbo boost vacuum actuator and the linkage arm moves back and forth to the extent I would expect is full range, about 3/4-1". I have also disconnected the vacuum hose and used a handi-vac type hand pump and it moved the same.
Does anyone know of more tests I could perform to figure this out?
The car runs good otherwise, and doesn't burn any engine oil.
Some of my thoughts are that it could be carbon build-up cutting down air flow in the turbo? Maybe choked airflow in the intercooler area?
The engine in this car was swapped out with a good lower mileage engine before I purchased it 4 years ago, by a diesel mechanic who also did work on VW's, and I believe he said the intake was in good shape/clean before it was put in. The timing belt kit was done at that time also.
Any suggestions are appreciated, THANKS!
Jeff


Did you take the clip off of the actuator arm to see if the turbo lever moves freely without any binding, also to see if the arm has full travel?
What kind of shape or your vacuum hoses in any leaks?


Sent from my iPhone using Tapatalk

Last edited by super1; May 18th, 2018 at 10:50.
super1 is offline   Reply With Quote
Old May 18th, 2018, 10:54   #3
BobnOH
not-a-mechanic
 
Join Date: May 2004
Location: central Ohio
Fuel Economy: 50/45/35
Default

Interweb guessing as well, I'm down at the turbo, specifically the actuator. Lots of other things it could be though.
Try the vacuum pump with a gauge on the actuator. It should just start to open at 3.5 to 5.0 "/Hg. Also observe how much to open all the way, iirc it's about 18(?). If it's close to but not in the 3.5 to 5 window, loosen the double nut, adjust the rod length until you get about 4. You can check if the vanes are frozen by operating the lever with your finger. If it's a bit sticky, exercise it, maybe even spray a little magic liquid on the vane area.
BobnOH is offline   Reply With Quote
Old May 18th, 2018, 13:00   #4
jeffbrom
Newbie
 
Join Date: Feb 2007
Location: Ohio
Default

Thanks Super1 and BobnOH, The vacuum lines are new silicone lines, replaced them a while back when this problem started. They hold vacuum well. I also checked the vacuum pump, no leak at the outlet fittings. I will try your suggestions on the vacuum measurements and the disconnect of the linkage, etc. That info is much appreciated. It might be a few days before I can get to it. Thanks, have a nice weekend!
jeffbrom is offline   Reply With Quote
Old May 18th, 2018, 13:06   #5
BobnOH
not-a-mechanic
 
Join Date: May 2004
Location: central Ohio
Fuel Economy: 50/45/35
Default

If you do remove the clip from the actuator rod, be warned, they get lost real easy. Use a magnet to catch it or a piece of tape or something so you can find it.
BobnOH is offline   Reply With Quote
Old May 18th, 2018, 13:13   #6
oilhammer
Certified Volkswagen Nut Vendor
 
oilhammer's Avatar
 
Join Date: Dec 2001
Location: St Louis
Fuel Economy: fantastic
Default

MIL on = DTC set.

What DTC? Over or under boost? OBD works, embrace it!
__________________
oilhammer
www.cardocautomotive.com
oilhammer is offline   Reply With Quote
Old May 18th, 2018, 17:59   #7
Nevada_TDI
Veteran Member
 
Join Date: Aug 2008
Location: Reno, sort of...
Default

As stated above. knowing the code will help greatly in solving your issue.
__________________
_______________
2001 Jetta GL TDI, Tinted, Ventectomy, Catectomy, EGR-ectomy, TDTuning, HIFLO .216's, Stealth 17/56 Garrett, VCDS Hex+CAN, South Bend Daily Driver 2 Clutch, DG Short Shifter, Previous Diesel: 1983 Rabbit Diesel
Nevada_TDI is offline   Reply With Quote
Old May 19th, 2018, 20:27   #8
mgoff5000
Veteran Member
 
Join Date: Aug 2009
Location: Danville, CA
Fuel Economy: 45 Jetta, 30 Passat (MPG)
Default

Since you have vag-com you really want to log what’s going on as you drive. There’s a guide here or on MTD about troubleshooting boost issues. I wasted a bunch of time hoping it wasn’t crunchy vanes but it was. I learned the most by disconnecting the actuator and trying to manually move the vanes. As noted, just buy a spare clip ahead of time. Hardware stores will have as “c” or “e” clips I think. If it doesn’t move well there’s a great guide on taking it apart and cleaning. Just be prepared to wait a day or more for the PBlaster to get through the rust so you can open it.
mgoff5000 is offline   Reply With Quote
Old May 20th, 2018, 10:12   #9
jeffbrom
Newbie
 
Join Date: Feb 2007
Location: Ohio
Default

Hello again,

Here is the code that is stored:

16618 - Boost Pressure Regulation PO234 - 35-10 - Limit Exceeded (Overboost Condition) - Intermittent

Please let me know where this leads as far as what to do or look at next.
Thanks,
Jeff
jeffbrom is offline   Reply With Quote
Old May 20th, 2018, 12:13   #10
super1
Veteran Member
 
Join Date: Apr 2010
Location: NY
TDI(s): none
Default Loss of turbo power around 3000-3400rpm

Quote:
Originally Posted by jeffbrom View Post
Hello again,

Here is the code that is stored:

16618 - Boost Pressure Regulation PO234 - 35-10 - Limit Exceeded (Overboost Condition) - Intermittent

Please let me know where this leads as far as what to do or look at next.
Thanks,
Jeff


I think you said you check the actuator? If itís not binding take the clip off the actuator arm and see if the lever of Turbo arm has full range without binding


Sent from my iPhone using Tapatalk

Last edited by super1; May 21st, 2018 at 10:13.
super1 is offline   Reply With Quote
Old May 20th, 2018, 12:30   #11
joep1234
Veteran Member
 
Join Date: Jan 2014
Location: NC
Default

Also check your fuel filter. If it's stopped up, you will only get enough flow to support a certain rpm range.
__________________
'04 Beetle TDI w/BEW and DSG
joep1234 is offline   Reply With Quote
Old May 21st, 2018, 04:16   #12
oilhammer
Certified Volkswagen Nut Vendor
 
oilhammer's Avatar
 
Join Date: Dec 2001
Location: St Louis
Fuel Economy: fantastic
Default

Sounds like you need a turbo, unless you can get the mechanism freed up. While certainly possible, but not as likely, it could be the VNT's N75 not being able to vent vacuum properly and/or fast enough.
__________________
oilhammer
www.cardocautomotive.com
oilhammer is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Power loss from around 3000-3500rpm loganwolverine VW MKIV-A4 TDIs (VE and PD) 5 September 4th, 2016 23:25
Power Loss over 3000 rpms Manu VW MKIV-A4 TDIs (VE and PD) 67 February 13th, 2015 15:16
Loss of power at 3000 RPMs bigbert VW MKIV-A4 TDIs (VE and PD) 9 November 19th, 2012 14:27
power loss at 3000 rpm dieselier TDI Power Enhancements 4 December 10th, 2002 00:56
Power Loss at 3000-3200RPM Ran TDI 101 3 March 26th, 2002 11:19


All times are GMT -7. The time now is 03:25.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
© 1996 - 2017, All Rights Reserved
Page generated in 0.17732 seconds with 12 queries
[Output: 110.86 Kb. compressed to 93.68 Kb. by saving 17.18 Kb. (15.50%)]