Bought car cheaply with problem already there. Fault 17965 turbo overboost was found by my mechanic tried a few things but nothing fixed the loss of power except turning the ignition off then back on whilst going along which solves it until the next time which could be the next few mins or next week? Mostly happens when overtaking or putting your foot down but can happen pulling away from 1st gear. My turbo went so replaced that with a re-con 7 months ago but that fault still remains. Vw currently have my car and after their diagnostic they claim the control arm in turbo has gone and they suggest a new turbo. Seems strange that both my turbos have the same fault and if thats really the only option why does the fault only occur occasionally? Should it still work sometimes?
This code is common. Usually the turbo vanes stick in the down position (builds boost quickly).
The way that the ECM protects the engine from too much boost, is by cutting fuel (power loss).
Once the key is turned off and on, the boost comes back until the next over boost.
November, 23, 2012 AT 3:33 PM
Did you find the video?
If the "bypass regulator valve" (vacuum solenoid) is always OPEN, then the turbo vanes will always be in the Fast Boost setting. Similar to being stuck down.
December, 9, 2012 AT 1:15 AM
Thanks for your reply. If I could please just ask you a few more questions as im so unsure what to do. I have looked at your video clips but they mean nothing to me as I am a young female and have no clue about mechanics. I have been taken the mic out of by expensive garages that all have different opinions on how to fix it but nothing ever works they just want to keep spending my money!
The mechanic Im using at the moment now suspects an electrical fault, hes reached that conclusion because the fault doesn't occur all the time. It is happening more and more frequent but is not all the time so he says he doubts a mechanical fault because it would happen every time I drive it. Do you agree with that?
How should I go about getting the vanes done if you think that would solve it ill go for it but I want to know if that is the case could the fault only occur sometimes? Or should it be present all of the time?
Also the turbo is only 7 months old so can the vanes get blocked that quickly?
What work should I say I want done at the garage?
How much should it cost? And can you recommend anywhere for me to take my car? I live in London SE9
December, 9, 2012 AT 1:42 AM
This fault can be intermittent even when the vanes are stuck... simply because it is all dependent on driving habit / style.
A gentle cruise through the city with frequent stops may never trigger this fault, where as a steep hill will trigger the
fault code quickly.
There are many Mechanics who are just not familiar with the way your TDi works... if your Mechanic is familiar with
VW TDi engines, then I will not question his troubleshooting process & conclusions.
A simple check is to see where the Vane Actuator Rod / Lever is sitting when the engine is OFF. If the rod / lever
is in the down position, then the vanes are stuck. I have uploaded a new video today showing rod and link movement
while the engine is running.
Get your mechanic to check this operation... if the movement is the same as in my video, then the vanes are fine and
the problem is something else:
After only seven months it could be that the turbo vanes are already stuck... or the intake manifold and EGR Valve are full
of carbon build-up.
I can free-up vanes between 15min to 1/2hr.... in severe cases where the turbo needs to be removed, labor can be more
than 4 hrs.
To find a qualified garage, have a look here: http://autorepair.iatn.net/ enter your location on the left and see if a VW
Specialty Shop comes up.
December, 9, 2012 AT 1:45 AM
If you are in Europe, then the Turbo Design / Layout might be different than in the North American Video Sample that I provided
but the operation is the same.
December, 28, 2012 AT 11:48 PM
i've spoken to my mechanic regarding your emails and he's happy to give it a try to see if it solves the problem but he has asked me to ask you how do you free up the vanes eg. New part, cleaning product? What is the procedure and he's not sure how you get to the vanes without taking out the turbo as he says its a very small area?
The best (but expensive) way to clean off the carbon, is to remove the turbo and disassemble / clean it.
I have had good luck with the above procedure (physically move the turbo vane rod while the engine is running) to free up the vanes.
I have had one customer who came back after one week with same issue... I believe I did not work the vanes back / forth long enough
and that is why he came back. Others have been fine for a couple of years.
Getting the turbo hot for an extended period of time with higher rpms (highway driving) can burn off carbon as well.
My method gives me an immediate visual verification that the vanes are free and that the code should not come back... a 5 to 10min test
drive after the repair (with scan tool attached) can confirm if boost pressure control is once again restored.
If he does not have success or if he thinks that this is not appropriate, then follow his suggestions, since I do not have the car in front
of me and can not confirm my initial thoughts.