[jojo1212]

hi all

car is passat tdi 2001, automatic 5speed 01v zf, AVF engine code

my car is loosing power every now and then
and u know to get the power back i have to switch off then on

so i hooked up the vag com cable, and it gave me this error

17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-10 - - - Intermittent

----------

so i checked all the hoses that starts from EGR to the turbo
all was fine ,, i didnt check the vacuum hoses
i changed them all instead with silicon ones according to some
article i found on the net with the right diameter
still the problem exists.

a year ago i had the same problem but with "Negative Deviation"
at that time i got the turbo out and cleaned it well

and just i did get the turbo out, cleaned it
very well , checked the vanes, the actuator rod
all works fine and great

put everything back, drive test it, still problem exists

i noticed that this problem occures more when the car is cold
when its hot it works fine most the time, but it dies on me other times

i hooked up the vagcom cable again and took the car for a test
to make a log file in block 11 or group 11 whatever u call it

http://www.2shared.com/file/o11bIGEi/LOG-01-011-x44xx-xxx.html

what do you guys think the problem is ??

thanks all

 

[Seatman]

Hi there, it might be a weak spring in the actuator for the turbo, I pressume yours will be a vnt turbo and not a wastegate. I'm not sure which car in the faq would have the same setup as you but it might be worth a look at some of the things that cause limp mode on the other tdi's, apart from that someone else might have some better info.

Non pd

http://www.myturbodiesel.com/1000q/multi/limp-mode-TDI-fix.htm

and pd

http://www.myturbodiesel.com/1000q/multi/limp-mode-TDI-fix.htm

welcometomyturbodies

 

[chittychittybangbang]

You've ruled out the vac lines, turbo vanes sticking, or actuator sticking.

It could still be the solenoid sticking, when you checked all the hoses, try a pressure boost leak test, it could reveal a leak that you can't see. And it could still be the rod length if you adjusted it.

 

[jojo1212]

thanks for your replies guys

how do i make a pressure boost leak test?? what tools do i neeed ?

 

[chittychittybangbang]

Take a look in the FAQ section for boost leak test.

 

[jojo1212]

i will

thank you

 

[jojo1212]

so i did the boost leak test, and it went fine, no leaks at all
so i swapped my n75 with egr solenoid to rule out any problem related to the n75
nothin changed , and n75 test through VCD output test showed that the n75 works
the actuator rod moved freely.

so i tried to lengthen the rod 1 turn by time and went to test drive
nothin helped no matter how many times i lengthened the rod , same error
so tried to shorten the rod a few times in hope of that might solve anything
still the same problem exist , OVERBOOST

in VCDs engine block 11 , my duty cycle shows 94% @ 4000rpm when idle
no matter how many times i lengthened or shortened the rod it stuck @ 94% @4000 rpm idle

what could cause this ???

 

[Seatman]

Could it be a dodgy map sensor? or maybe you could try cleaning the plug for it see if it helps, it's free anyway

 

[jojo1212]

i tested the map sensor, and cleaned the plugs a couple of days ago , that didnt help

 

[asterix3k]

did you find a answer to your problem, i have the same as you..

thanks

yan

 

[Seatman]

What about pressure testing the actuator? Not the N75 but the actual cylinder thing connected to the turbo? Like I said earlier the spring can become weak and cause over boost. There's not a lot else I can think would cause overboost, underboost is easier because that can be a leaky pipe or vac line but overboost with a vnt turbo is different, the vacuum is required to create any boost at all so any vac leaks and I doubt you'd get boost. The N75 is a possibility but you've ruled that out and you say the lever on the turbo moves fine so that doesn't really leave much else. I imagine the actuator should move X amount of distance per X amount of pressure applied with a vacuum pump. I have read though on other forums of the spring being weak and causing the issue so I would look into it.

 

[asterix3k]

Hi Seatman,

my actuator is new, i swapped the N75 valve with the egr one and no changes. mabye one thing i have to check is the rod length of the actuator. mabye it makes the turbo over boost.. ? is it possible? this week i will change all vacuum lines. and test it if i get 22'' in hg to test the vacuum pump.

byee