TDi Limp mode

Non ACVW models.
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

TDi Limp mode

Post by eben »

Throwing this out there before I dig deeper... anyone managed to resolve similar issues?
My 115hp TDi is having some limp mode issues.
First a few comments about what is strange in comparison with my other TDi:
  1. Especially when engine is cold in lower gears, there is quite a loud turbo cavitation sound when changing up.. (absent in my other TDi)
  • Cycling the VNT actuator, the turbo spools up quite loudly... is this normal?
  • Goes into limp mode at ~3500 rpm in 3rd.
  • The actual maximum pressure does not seemed to be measured by VAG-COM.(maybe faulty boost sensor?!)
Do you have some advice for me after looking at the video?

Thanks a lot.
Eben


User avatar
retrovan
Donor
Donor
Posts: 8294
Joined: Mon Feb 07, 2011 8:51 pm
What model do you have?: 52T1,68FB,72Bay,75FL
Location: Eich! no, in Jefferys Bay
Has thanked: 254 times
Been thanked: 481 times
Contact:
Netherlands

Re: TDi Limp mode

Post by retrovan »

@ eben

Sorry buddy, can not help, but have a look at this site, may do something for you.

Herman

http://www.myturbodiesel.com/wiki/limp- ... di-engine/
Last edited by retrovan on Sun Mar 02, 2014 11:04 pm, edited 1 time in total.
1952 Split Beetle 1835cc (Azure Blue)
1968 Fastback 2Lt.type4( Red)
1972 Low Light Bay Panel Van 2Lt type 4(White)
1975 Fleetline Panel Van 1914cc (Aqua Blue/White)
2019 MeFusco Beetle Truck
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

Re: TDi Limp mode

Post by eben »

Been there already :) Thanks
I've got two main suspects:
1. Sticking VNT vanes because of sooting...
2. Faulty boost sensor...
User avatar
Tony Z
Donor
Donor
Posts: 14787
Joined: Wed Sep 14, 2005 8:33 am
What model do you have?: 2.3L 69; 1302; P/Van
Location: Klipheuwel (near Durbanville), Cape Town or working at sea
Has thanked: 150 times
Been thanked: 443 times
South Africa

Re: TDi Limp mode

Post by Tony Z »

first check that any hoses you have on the system are all in good condition
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

Re: TDi Limp mode

Post by eben »

@Tony Z hoses are OK. There is no "creep" on the actuator because of leakage as you can see. :)
User avatar
splitfan
Carburettor
Posts: 1961
Joined: Fri Jul 20, 2007 1:23 pm
What model do you have?: 56,71,75
Location: Port Shepstone KZN
Has thanked: 45 times
Been thanked: 26 times
Contact:

Re: TDi Limp mode

Post by splitfan »

eben wrote:Been there already :) Thanks
I've got two main suspects:
1. Sticking VNT vanes because of sooting...
2. Faulty boost sensor...
Hi Eben , plugging in a diagnostic tool would confirm which one is the culpret , they are both common faults and its a 50-50 toss-up without a fault code.
Our local cars suffer from the vanes getting clogged but i suspect you guys have a better diesel over there (with emmision laws being enforced) but the fact that there is also a wine from the turbo suggest you problem lies within... boost sensor would not cause a turbo whine.
good luck and keep us updated
My biggest fear is that my wife sells my cars for what i told her they cost !!
User avatar
splitfan
Carburettor
Posts: 1961
Joined: Fri Jul 20, 2007 1:23 pm
What model do you have?: 56,71,75
Location: Port Shepstone KZN
Has thanked: 45 times
Been thanked: 26 times
Contact:

Re: TDi Limp mode

Post by splitfan »

What fault codes are you getting under engine ?
My biggest fear is that my wife sells my cars for what i told her they cost !!
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

Re: TDi Limp mode

Post by eben »

Thanks @splitfan.
I'm getting "Charge Pressure Control: Positive Deviation"
http://wiki.ross-tech.com/wiki/index.ph ... 557/005463

Maybe I should try force the vnt slightly to see if it is reaching the stops...
User avatar
splitfan
Carburettor
Posts: 1961
Joined: Fri Jul 20, 2007 1:23 pm
What model do you have?: 56,71,75
Location: Port Shepstone KZN
Has thanked: 45 times
Been thanked: 26 times
Contact:

Re: TDi Limp mode

Post by splitfan »

Hi Eben
As you might know , that means the car is overboosting , the std management has pre set parameters for boost press at certain rpm ranges whats happening now the vanes are stuck or cant move to the correct position thus creating the overboost fault .I see a turbo removal in your future hopefully the nuts and studs on the turbo are not to rusted/heat treated that you get them out without any breaking good luck. You can take out the boost sensor usually they are mounted on the intercoolers and give it a clean with some carb cleaner but my money is on the turbo being the culprit.You might want to look at the turbo oil feed and return pipes while you are at it.
My biggest fear is that my wife sells my cars for what i told her they cost !!
brianj
Single Port
Posts: 1253
Joined: Wed Jan 17, 2007 8:56 pm
What model do you have?: 67DC 66Fasty, 71West
Location: JHB
Has thanked: 13 times
Been thanked: 9 times

Re: TDi Limp mode

Post by brianj »

Check the vacuum pipes on the actuator? Check the basic physicals before replacing the wizardry
supervly
Oil Leak
Posts: 67
Joined: Thu Jul 22, 2010 9:51 am
What model do you have?: Beach Buggy , Syncro
Location: Somerset West Cape Town
Has thanked: 2 times
Been thanked: 2 times

Re: TDi Limp mode

Post by supervly »

http://www.youtube.com/watch?v=Z7k5yE1FAJs

This is interesting , they claim you can clean the vanes without having to remove turbo - depends on what Tdi you have , not much space to work with in Polo

I have removed my turbo 5x in last 3 weeks and can do it in 2 hours flat

Ohh yeah word to the wise DO NOT RECONDITION just buy a new one if damaged , cleaning is OK

regards
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

Re: TDi Limp mode

Post by eben »

I've heard of this yes.. About €40
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

Re: TDi Limp mode

Post by eben »

This is what it's like without load.... This can't be right... doesn't happen with my octavia... The turbo should not be spooling like this without load.
Must be sticking vanes..
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

Re: TDi Limp mode

Post by eben »

Fixed it with oven cleaner...
Lets see how long it lasts..
Before and after graphs:
Yellow = Actual Boost
Green = ECU requested boost
Red = Engine Speed
Grey = Boost controller duty cycle.
Overboost.jpg
You do not have the required permissions to view the files attached to this post.
User avatar
eben
Site Admin
Posts: 6449
Joined: Tue Sep 13, 2005 3:40 pm
What model do you have?: None
Facebook: www.facebook.com/ebenve
Location: Fintice, Slovakia
Has thanked: 91 times
Been thanked: 54 times
Contact:
Slovakia

Re: TDi Limp mode

Post by eben »

If anyone is interested, this is how I did it:
  • Remove the EGR to Exhaust manifold hose.
  • stick some flexible tube in there carefully so it goes to the HOT side
  • using a head with a tube (like you get for oils spray), spray foaming oven cleaner(Mr Muscle supposedly works best) into the pipe while clamping the top to make sure it goes down the tube.
  • keep going until the foam just comes out or the EGR hole (it should not go up the exhaust manifold to the head!)
  • Let is sit for about 5 minutes
  • Using some pliers, carefully start manually moving the VNT actuator. YOu will find that is starts moving with less resistance.
  • Let it sit a bit more
  • WOrk the actuator repeatedly about every 15mins until you feel that it is moving freely and through the whole range or movement.
  • Replace your EGR pipe
  • Start the engine and rev it to min 3000 for about 30sec - 1 min, making sure your exhaust points to somewhere that you don't mind getting dirty.
  • Check everything runs OK and go for a nice brisk drive using WOT in 3rd gear upwards to see if your engine is not going into limp mode anymore...
PS this is assuming your issue is sticky/dirty VNT vanes... this will not fix other issues with your turbo ie. seals, actuator leaking etc.
Post Reply