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Limp Mode

Printed From: The Brick-yard
Category: T5 Section
Forum Name: T5 Chat
Forum Description: Forum for T5 specific chat
URL: http://www.brick-yard.co.uk/forum/forum_posts.asp?TID=74163
Printed Date: 19 Apr 24 at 14:39
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com


Topic: Limp Mode
Posted By: brownster
Subject: Limp Mode
Date Posted: 30 May 12 at 18:21
Hi Everyone

Has anyone had problems with Limp mode? My 130 axd engine is fine when I rev and pull away from standing. In fact everything is fine until i hit a hill at 65/70mph. Then as soon as revs go a notch above 2000 limp mode kicks in. It does't do it all the time though.... weird.

The van has done 140k. for the last 40k since I've owned it i haven't replaced any sensors. Had it plugged in to VAGCOM and over boost was in the fault codes. The problem doesn't turn the engine warning light on. The indy that i've taken it to said all sensors are showing good continuity except one but doesn't think that is causing problem. instead he thinks it could be the turbo. reckons a vane is knackerd. does this sound true? if so why have i got plenty of boost and no limp mode from standing... even hill starts?

Problem started about 2 years ago but last week on a run to cornwall (250mile) was quite frequent.. turn off and on = ok for 10mile or so.

I need van this weekend for a trip to holland. Should i just get him to replace the sensor? or allow him to strip turbo off to have a look? 

Please help!!


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T32 140 Kombi Facelift Metallic Natural Grey



Replies:
Posted By: Rebuild
Date Posted: 31 May 12 at 02:17
The variable vanes in the turbo tend to stick, especially if driven gently all the time, leading to overboost error codes.
They need an Italian tune up once in a while.
Most likely your turbo is mechanically ok,just clogged with soot.


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Steve
2004 T5 2.5 TDI


Posted By: gregozedobe
Date Posted: 31 May 12 at 03:42
WHS ^ 

There are a few posts around (either here or on the tdiclub site IIRC) on how to clean out the variable vanes and get them moving again, but it seems to be a fiddly and messy job.  The "italian tune-up" method may work if they aren't too sticky, but yours sounds like the vanes on your turbo may need to be cleaned out manually.

Switching off and back on resets the limp-home mode, but as you noticed as soon as the revs go above approx 2,000 rpm under load the sticky vanes cause the over-boost problem again and the ECU shuts down the fun to protect the engine.


Posted By: Steve B
Date Posted: 31 May 12 at 07:42
brownster if it is sticking turbo vanes....have a read of http://www.brick-yard.co.uk/forum/innotec-turbo-clean_topic62022.html?KW=turbo" rel="nofollow - this http://www.brick-yard.co.uk/forum/innotec-turbo-clean_topic62022.html?KW=turbo" rel="nofollow - thread to see how to clean the turbo.


Posted By: Rebuild
Date Posted: 31 May 12 at 13:29
http://forums.tdiclub.com/showthread.php?t=179589" rel="nofollow - http://forums.tdiclub.com/showthread.php?t=179589
 
There are a number of different reasons why the car may overboost… some being very simple to verify and fix and others more complex. The majority of overboosts are created by:

Bad Maf (Oxygen Sensor)
Leak in the vacuum system
Faulty N75
Bad actuator
Dirty gummed up turbo causing variable vanes to jam or stick

Some members have experienced overboost due to coked up intakes as well. This is a maintenance issue.


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Steve
2004 T5 2.5 TDI


Posted By: Chauffeurdude
Date Posted: 02 Jun 12 at 09:46
Hi mate. My starship mileage Shuttle (AXD) has had overboost problems for some time. Cured now with new turbo as died couple of months ago!! Was never convinced about vanes sticking as would rev freely and spin up to 3500rpm under load. Seemed to do limp mode more for my driver as he was bit more on/off throttle than me and would boot it at low revs!! Only once or twice a week though (1000+ miles per week). At one stage got worse and was doing as you describe, this turned out to be a wiring fault. Looking at engine from front rhs you have an intercooler pipe that runs under EGR valve area to intercooler. There is a sensor in this pipe and if like mine the plug is on the top and wire bends tightly over and back down to loom then this could be your problem. Mine had a broken wire where it bends round out of the connector as it appears to be under stress!! As wire had broken into connector block we found another connector with reasonable length of wire, spliced it in so wire was bit longer, ran it round so less stress on the connector and with couple of cable ties fixed!!! I did hear (unconfirmed ) that this was a common problem. Certainly fixed it for me!! Certainly worth checking out as cheap fix!! Hope this helps. Cheers, Craig

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Owns VW Transporter T5 Shuttle SE 130 TDi.


Posted By: T5 TDI
Date Posted: 02 Jun 12 at 09:49
How many miles now Craig?  Are you going to make the half a million mark?  Tongue

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2004 2.5 174


Posted By: Chauffeurdude
Date Posted: 02 Jun 12 at 10:01
Hi again mate. Currently 381,000 miles. Can only keep it till November under licensing laws so should make 400,000 in my ownership. My mate wants it as family hack so looks like sold already!! Old girl has been struggling though this year!! Tiptronic box went again in Feb, out of warranty of course so £1500 again!! Turbo went in April (original one) so wrong end of £1000. Started bumping back through intakes couple of weeks ago so knew cam/followers were mullered!! Just done that and back on road last week!! Cam was a fun job, my mate managed it with none of the special tools etc. Anyway still going for the moment!! Nice to hear from you. Aplogies for thread hijack!!

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Owns VW Transporter T5 Shuttle SE 130 TDi.



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