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 > VW TDI Discussion Areas > TDI 101

TDI 101 Got a simple/basic TDI question? Are you a newbie (new to the forums). Feel free to post your question here.

Reply
 
Thread Tools
Old December 4th, 2017, 06:17   #1
countrykid
Newbie
 
Join Date: Dec 2017
Location: usa
Default P1592 rough running suddenly

My check engine light came on as I was heading home on the expressway. When I got home I had the code read and there was a turbocharger/supercharger code. After the code was read the car was in limp mode until I turned the car off and turned it back on. The car was fine until I made my next trip with it. The light came in again after being cleared and still ran fine. At the end of my trip I pulled off the freeway and the car suddenly ran horrible. On spool up it jerks and vibrates when trying to accelerate. There is also excess smoke. I have mechanical expierence but am slightly new with the vw. Any hep is appreciated thank you!
countrykid is offline   Reply With Quote
Old December 4th, 2017, 07:35   #2
Mongler98
Veteran Member
 
Join Date: Mar 2011
Location: Northern MD
Fuel Economy: Race: 12mpg, Gandma:65mpg
Default

Limp mode. Next time when it does this, turn the key off and then back on, if it fixes the issue for a few minutes or moments, you are going into limp mode. Limp mode is triggered by over boosting for a period of time (about 5-10 seconds). This is the most common issue. its usually caused by a bad vac (boost) line to something that causes the waste gate actuator to not work properly when commanded.
Common issues and the fix for them.

Vacuum lines or boost lines: Inspect or replace them all. usually 3mm, 4mm and 5mm hoses. dont use cheep ones, get quality silicone or VW braided lines from IDparts.com or where ever. Not sure about your ECU but on MK3's there is a boost line going into the ecu and inside the ecu to the MAP sensor and it needs replacing too, if you have one.

N75 Valve: you should have a slight clicking from it, kinda like a CCV valve. some times you can clean them, they are not very cheep ($75) for an OEM. usually replacing it is best.

MAF: this is the sensor on the intake air duct right after the filter. ONLY CLEAN WITH MAF cleaner. A cold air intake usually is the culprit for killing them. Check out this link to understand why. Disconnect it and if driving conditions do not improve then its bad. (only after you make sure you have no boost leaks and all your lines are perfect shape.) http://forums.tdiclub.com/showthread.php?t=290373

Boost leaks: Check all your pipes after the turbo to and from the intercooler and to the intake manifold. take them apart, and put back together to make sure no cracks etc. inspect the intercooler too. You will see some oil on the pipes. Its normal. Just wire off the parts your connecting with a light amount of brake clean on a rag. DO NOT spray it into or on the pipe. it could cause a temporary runaway. Happend to me lol, i was lucky, kinda.


thats about it. Fix and inspect those items. in that order one at a time with test drive in between to make sure you dont jsut thorw parts at it.

From what you described, Vac lines, turbo actuator, and you have a boost leak, BAD too, your IC pipes and boots, check them
Mongler98 is offline   Reply With Quote
Old December 4th, 2017, 09:39   #3
BobnOH
Veteran Member
 
Join Date: May 2004
Location: central Ohio
Fuel Economy: 50/45/35
Default

Sudden rough running sometimes occurs when one of the big pipes get loose, usually its underneath.
BobnOH is offline   Reply With Quote
Old December 5th, 2017, 12:28   #4
countrykid
Newbie
 
Join Date: Dec 2017
Location: usa
Default

Is there a way to pressure test the system for boost leaks? Initially when the engine light came on and the car went into limp mode I was able to turn it off and restart it causing the limp mode to go away. Now the problem is steady but is not limp mode. I inspected the intercooler hoses and connections and they appear to be fine.
countrykid is offline   Reply With Quote
Old December 5th, 2017, 14:17   #5
UhOh
Veteran Member
 
UhOh's Avatar
 
Join Date: Dec 2014
Location: PNW
Default

There's no substitute for some sort of data reporting device. Running an Ultragauge/Scangauge or VCDS can really help pinpoint issues. Lots of times when not under pressure (load) -which is when you're looking- loose connections/holes etc won't be visible. But, that said, I wouldn't jump to conclusions that this is necessarily a boost issue (probability says yes, but w/o actual data you're only going to be guessing).
UhOh is online now   Reply With Quote
Old December 7th, 2017, 12:29   #6
countrykid
Newbie
 
Join Date: Dec 2017
Location: usa
Default

Last night the car actually started running better and had full power (more boost) for a brief period. After getting the codes read again they shop failed to mention another code P0102 which is MAF. Cleaned the sensor with MAF cleaner and reassembled. The problem still exists but gave me a further clue. The boost sort of comes and goes now and then, also if the car is running with no boost and I restart it, it becomes slightly better. Could this be the n75? If so the only way I can find one is online, is there a substitute valve or method for temporary use?
countrykid is offline   Reply With Quote
Old December 7th, 2017, 12:38   #7
BobnOH
Veteran Member
 
Join Date: May 2004
Location: central Ohio
Fuel Economy: 50/45/35
Default

Check the N75 wiring is good. The device itself simply adjusts vacuum flow, so no, the N75 wouldn't do that. There is a vacuum line runs to the air box sometimes gets left off, doesn't usually affect much.
Have you seen this? From Ross Tech wiki, great resource.
BobnOH is offline   Reply With Quote
Old December 7th, 2017, 14:42   #8
oilhammer
Certified Volkswagen Nut Vendor
 
oilhammer's Avatar
 
Join Date: Dec 2001
Location: St Louis
Fuel Economy: fantastic
Default

Does the engine start and idle OK? Sound normal? Not missing or making a loud "bump-bump-bump" sound?

The VNT actuator is easy to check. You can get to the vacuum line up top on the BRMs. Pull it off and stick a small vacuum hose down on it attached to a hand held pump, or in a pinch, your mouth. Suck on it, the rod should move up and stay put (yeah, I just typed that, stop laughing you pervs... ).

A smoke machine works great to find small boost leaks. The big ones are easier to find.
__________________
oilhammer
www.cardocautomotive.com
oilhammer is offline   Reply With Quote
Old December 7th, 2017, 17:38   #9
countrykid
Newbie
 
Join Date: Dec 2017
Location: usa
Default

The car starts good and idles good as well. When this happened I was driving the car steady for hours and then lost power when I pulled off the expressway. Currently power goes up and down and car is very smokey.
countrykid 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
running rough after running super low on fuel soccerhead16 TDI 101 1 December 14th, 2014 18:48
Suddenly stopped running Zippy1 VW MKIV-A4 TDIs (VE and PD) 37 June 2nd, 2009 15:58
running rough.... golden01 General VW Discussion 0 October 8th, 2008 15:51
Rough Running nicknack2 TDI 101 11 March 17th, 2008 12:52
Engine suddenly stops running? dslemaire VW MKIII-A3/B4 TDIs 8 November 4th, 2006 15:50


All times are GMT -7. The time now is 03:02.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2017, 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 0.13293 seconds with 12 queries
[Output: 91.24 Kb. compressed to 78.36 Kb. by saving 12.88 Kb. (14.12%)]