130tdi limp mode problem.

[FARA]

Hi can anybody please help. Three weeks ago whilst out driving I accelerated hard in my 2003 130PD estate and noticed some black smoke (soot) in my rear view mirror. I stopped at some traffic lights and as I pulled away I noticed the car had gone into limp mode. I got the car home and restarted it and it was if there was nothing wrong. The turbo kicked in and she ran great - in fact better than ever.

However, I was out again today and exactly the same happened again after I had put my foot down black smoke (soot)...

Can anyone please advise what they think the problem maybe.

[kenney]

There are a few items which relate to your problem,but the first thing you need is a fault code read.

[calum]

If you car has the variable vane turbo , then chances are the vanes are starting to stick . This can cause overboost which results in limp mode . Good news is that you can fix it yourself if you are mechanically minded , Calum .

link: http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html

scroll down , this is how the vanes should work .

[FARA]

Thanks Calum. I have booked it into my local VW specialist on Thursday to get the fault codes read. I thought it maybe sticking vanes/ actuator or the N75 solenoid playing up.

Bearing in mind its location, how difficult a job is it to remove the turbo from the car.

[calum]

FARA , I don't know about removing the turbo as I have a 1.8t not a 1.9tdi , but in saying that if you can twirl a spanner it should be more time consuming than hard . I think it's booked at 3 hours to remove , hope this helps . You can test the vane action by hand do a search , before you spend any hard earned cash , Calum .

[FARA]

Cheers Calum - will do. When you say test the vanes manually is that by pushing the actuator rod by hand or by removing the little vacum hose and checking the travel.

[calum]

Hi Fara , well .... both really , the actuator should move freely and smoothly by hand and the vacuum will only give problems if there is no vacuum .

[FARA]

Thanks for your help Calum. It's going to be really tricky with the dark nights but i'm going to try and leave work early tomorrow and take a quick look.

[scotty33]

Hi

Take care not to disturb the adjusted length of the actuator rod, get this wrong and the car could overboost/underboost. Easiest way to check it is all free, is to remove the 2 nuts (or is it bolts?) which secure the VNT actuator to it's mounting bracket.
The rod shortens under vacuum to give boost and extends when the vacuum is taken away.

[martin1810]

It's a free country but I think you should follow kenneys advice first before you start taking things apart.

[Izalman]

easy to check the VVT action on the turbo, with the engine running look at the vacuum actuator and the little link going into the turbo. Turn off the engine ( will require a second person) actuator arm should move down approx 8 -10mm.
Having experienced limp mode myself, changed N75 valve = no change. Turned out to be MAP ( Manifold absolute pressure) sensor faulty.This measures boost pressure & temp - feed info into ECU. 10 min job to change - located on big air pipe near rear bulkhead with 2 screw holding it in. £35 approx from dealer they call it a thrust sensor...

[FARA]

Big thanks very to everyone that answered this thread. Just got the car back from the VW Specialist. They did the following - vas5052 test shows fault code 17965 p1557, turbo charger overboost condition control limit exceeded. They said it could be the
n75 playing up as it is usually the most common cause, so they replaced it. Incidentally, the original didn't show any problems when tested.

They also carried out a road test and said the car is running fine, no fault codes, limp mode problems etc. There is a note on the bill stating if the problem persists then a new turbo will be required.

[Laurie2212]

Big thanks very to everyone that answered this thread. Just got the car back from the VW Specialist. They did the following - vas5052 test shows fault code 17965 p1557, turbo charger overboost condition control limit exceeded. They said it could be the
n75 playing up as it is usually the most common cause, so they replaced it. Incidentally, the original didn't show any problems when tested.

They also carried out a road test and said the car is running fine, no fault codes, limp mode problems etc. There is a note on the bill stating if the problem persists then a new turbo will be required.

Hi

I was in the same boat in August - Skoda main dealer quoted £1500 for new turbo. I was gutted to say the least. After research on the forum and advide from the experts I went down a different route: Local independent removed turbo, Midland turbo collected it, re-built it (£185 + VAT) delivered it back in 3 days. and the local indepedent re-fitted it. Full cost just over £500 (which included a new MAP sensor, oil pipe, gaskets etc) Thanks to Crasher and Martin for their advice at the time - saved me £1000 and stopped me from trading in a pefectly good car (I was upset at having to spend £1500 on a car worth about £2000 at best).

Hope you get sorted.

Regards

Laurie

[FARA]

Cheers Laurie, It looks like I'll have to run with it and see how I get on for the time been. I will have ago at checking the actuator arm over the weekend weather permitting.

[cptk]

Hi, I to have had, or should I say STILL have problems with my A4 1.9 tdi 130BHP 2002. The car keeps going into limp mode, have read through loads of advice and possible causes for this problem but I’m still no nearer to sorting out the problem either.
After getting the car checked out on the computer several fault codes showed up, so to be on the safe side first I replaced the EGR valve, then the MAF sensor, then the exhaust sensor. After re-checking on the computer, then clearing all codes I took the car for a long run, unfortunately the car still looses power and appears to go into limp mode, the only way I can clear this, is to switch the ignition off then back on very quickly, then the car is ok, sometimes for a while but the fault always comes back again (very intermittent) I spoke to a chief technician at Audi and he said that from their experience the veins in the turbo heat up and can cause them to distort, this in turn causes uneven pressure, which in turn sends a signal to the ECU as turbo over boost and puts the car into limp mode...
However I’m not convinced, a friend has suggested that check the turbo boost by connecting a turbo boost gauge, does anyone know what it should read, and if I’m barking up the wrong tree. I have been trying to sort out this problem for the past 5 months, can anyone help or offer any more advice.
Regards, Karl

[martin1810]

Surely the code read will tell you if you have high pressure or low pressure logged as a fault. High pressure fault codes are often turbo vanes sticking.

[cptk]

No, checked again today, no fault codes are showing:boggled:

[kenney]

What is the engine code?exhaust sensor, which one?

[cptk]

Not sure, but will get back to you.