turbo cutting out on passat - loss of all power

[03jnz]

I have owned a vw passat ('03) for the last two years. from the day i bought it the turbo has been cutting out regularly, especially if the car is under a greater load ie going up hill, more weight / passengers. the problem is fixed if the car is turned off then on again. here is a list of things that i have done so far to remedy the problem:

new turbo fitted, three different airflow meters fitted, boost pressure sensor changed, manifold pressure sensor replaced, replaced bottom pipe on inter-cooler (also noticed oil passing into the inter-cooler)

the car has been seviced regularly: air filter, oil filter/oil change etc.

for some reason fitting a tuning box helped reduce the frequency of the cut out, for reasons i don't understand.

the last thing i tried was removing a pipe going into the egr valve. i drove the car for two miles to see if there was any difference and then replaced the pipe. since then the problem appears to have worsened. should i replace the egr valve???

any help or advice would be great. i love the car bar this one very very very very annoying fault.
best regards
paul

[scotty33]

I have similar sounding symptoms with my '01 130 tdi, I have read the fault codes and mine is an overboost problem.
From what I've been reading, this is usually caused by: (in no particular order) sticky turbo vanes (VNT mechanism), a problem with the VNT actuator, the boost control valve (N75) or a leak somewhere in the vacuum pipework to the N75/VNT actuator.
I suggest you check the small vacuum pipe system back from the turbo, if no joy, then find somebody near you with vag com to scan it for a definite diagnosis?

[Sammasonyamaha]

First take the pipe off the n75 valve and make sure the pipe going to turbo actuator will hold a vaccume when you suck on it, sometimes the seals on the actuator go causing it to be open to atmosphere. If this is ok check the pipe from the vaccume pump on the end of the cam shaft. There is a small valve to keep pressure in the brake servo line. Take this valve off and ensure it is not blocked with carbon as this is quite common also. Hope this helps

[Sam]

Good advice albeit 6 years too late

[Sammasonyamaha]

Haha I see that after!!!!