turbo vacuum pipe layout.....

[ini]

The blocked off tube is your atmospheric feed for the N75 boost controller & EGR.

It should attach at the top/rear of the airbox.

If the nipple is broken, the tube needs to be open to the atmosphere, but it does need to be filtered (maybe an old petrol inline fuel filter would work)

The hole in the back of the airbox also needs sealing, as unfiltered air is getting in.



Your boost control is not working properly with the tube plugged, the vacuum can not be regulated.

Make sure your N75 does not have any blockages (energise and blow out) and maybe squirt some WD40 in it.

Also work the rod/lever under the turbo vac actuator up and down to ensure it is free. Pull the rod upwards towards the actuator to close vanes = high boost position. It can be hard to grab as the bracket is partly in the way.

Attaching a tube to the turbo vac actuator and sucking will move the mechanism fractionally, but you need a very powerful suck, lol. The return spring is very powerful on the GT17's and needs a lot of force even by hand.

[Robbycroft]

pics are no good, just took them at dinner time.

It seems i have two pressure converters but no-where to put this random pipe, i dont' even know if it sucks or blows.

[SS069]

Right here we go --------->

- I have sealed the hole in the aircleaner box to eliminate any un-metered air
- I have cleaned the EGR & put it back to how it should be - not much difference
- I have checked the vac pipes, they're as they should be
- I have revved the car - the turbo actuator arm does move
- I replaced the MAF - no real difference (with a genuine OEM part from GSF carparts)
- I have isolated the EGR actuator & blocked the vac pipe - less power & less soot from the exhaust

so...my next step, I'm going to remove the turbo & clean iot with Mr Muscle foam oven cleaner..............so watch this space...........

anyone have any more suggestions what it could be, the car does hunt on steady throttle between 15 & 50 MPH

[ini]

If your turbo vac capsule is holding vacuum (not perforated) it is 99% definitely your vnt mechanism.

Does it make a 'crunching' noise when you move the actuator?

If you can feel even the slightest 'catching' when you move it, it is sticking enough to limp.

It is most likely totally jammed up solid.

The rod/lever hole can also oval causing limp mode, but i think your problem is just vnt crud related.

[SS069]

If your turbo vac capsule is holding vacuum (not perforated) it is 99% definitely your vnt mechanism.

Does it make a 'crunching' noise when you move the actuator?

If you can feel even the slightest 'catching' when you move it, it is sticking enough to limp.

It is most likely totally jammed up solid.

The rod/lever hole can also oval causing limp mode, but i think your problem is just vnt crud related.

cheers ini, but it doesn't go into limp mode it's just like driving a normally aspirated diesel car......I'll try & get it cleaned out over the weekend & post it on here

[SS069]

right ->

After replacing the air flow meter on the air filter box .............with a genuine part from GSF @ £65 inc VAT..................

I've now cleaned the turbo with Mr Muscle oven cleaner & kept moving the turbo actuator arm every 15mins for a minute or so, this was done over a period of 2 hours to make sure - the turbo wasn't that dirty inside.........

Results - still no real change & the car still emits lots of soot from the exhaust when revved - when stood still & revved the car leaves a soot imprint on the floor below the exhaust from a couple of revs

so what's the next step

I've also repaired some wires that run below the engine along the bottom of the radiators - there were 4 wires all brown with different coloured lines on them - I don't know what they're for but ythey were melted together after being rubbed against the bottom pulley of the AC belt.........

[ini]

Make sure that the turbo vac capsule is getting a vacuum.

If it is a 110+, and your vnt mechanism does not move, the turbo vanes are free, and the vac capsule is ok, it must be a problem with the n75 or vacuum/air supply to it?

If it is a 90bhp the turbo actuator will not move until you have too much boost?

[richardpshort]

Hi Let me have your engine code and your e.mail address and i will send you a diagram

Hi, I'm sorry I'm new to this site and unsure how it works. I have an Audi A4 1.9TDi (90) and have the same problem as the previous query. I have a vacuum hose which is clipped to the bulkhead but doesn't connect to anything and is simply floating around the area of the air-con pipes. Can someone please advise me or send me a vacuum hose schematic for reference.
Regards. R

[kenney]

need your engine code

[richardpshort]

z1
Thanks