Vaccum Line Reduction

[Monster Stealth]

Has anyone ever performed a vacuum line reduction on the 1.8T engines? Seeing as I have read about so many leaks from certain hoses in the system, I can only see good things come from the simplification. I come from the 3000GT/Stealth platform and am in the process of installing a catch can and krank vents on my 3000GT and decided it would be a good idea to do it to the A4 as well, since they are both turbo charged. First why in gods name are there so many check valves in this system? Is the pancake valve the actual pcv valve or does that just act as a restrictor between the TIP and the crankcase? I really would like to simplify out vacuum line system, but am really confused with the pcv system and vacuum diagrams. Maybe it will be easier once I tear into it? Any help is appreciated guys.

[Monster Stealth]

Does anyone have a key to this vac diagram? Is #16 the PCV, or is the pancake valve actually the PCV?

[Stampy]

Isn't that for an AWM?

[Durkin]

if you have a 99, you have an AEB. that is for an ATW (2000)

Charge air regulation, overview for engine code AEB

Vehicles with manual transmission
1 - Pressure regulator valve
For crankcase ventilation
2 - Evaporative Emission (EVAP) canister purge regulator valve -N80-
3 - To Evaporative Emission (EVAP) canister
4 - Check valve for Evaporative Emission (EVAP) canister
Installed position (light/dark): as shown in illustration
5 - Turbocharger
6 - Fuel pressure regulator
7 - Intake manifold
8 - To Leak Detection Pump (LDP) -V144-
9 - Crankcase ventilation
10 - Check valve for Evaporative Emission (EVAP) canister
Installed position (light/dark): as shown in illustration
11 - Charge air cooler
12 - Pressure unit
For wastegate
13 - Charge pressure bypass valve
Checking Page 21-11
14 - Wastegate bypass regulator valve -N75-

[Durkin]

Does anyone have a key to this vac diagram? Is #16 the PCV, or is the pancake valve actually the PCV?

That was for an ATW

Charge air regulation / secondary air vacuum control, overview for engine code ATW
1 - EVAP canister
2 - From fuel tank
3 - Evaporative Emission (EVAP) canister purge regulator valve -N80-
4 - Check-valve for EVAP canister
Between EVAP canister and intake manifold before turbocharger
Installation position (light/dark side): Arrow points in direction of flow, as shown
5 - Air cleaner
6 - Turbocharger
Check charge air pressure Page 21-51
7 - Combination valve for secondary air injection
8 - Fuel pressure regulator
9 - To power brake booster
10 - Check valve
Installation position (light/dark side): Arrow points in direction of flow, as shown
11 - Vacuum booster
12 - To Leak Detection Pump (LDP)
13 - Vacuum reservoir
14 - Distributor piece
15 - Check valve
Installation position (light/dark side): Arrow points in direction of flow, as shown
16 - Secondary Air Injection (AIR) solenoid valve -N112-
17 - Crankcase vent
18 - Check valve
Installation position (light/dark side): Arrow points in direction of flow, as shown
19 - To tank Leak Detection Pump (LDP) -V144-
20 - Check valve
Installation position (light/dark side): Arrow points in direction of flow, as shown
21 - Charge air cooler
With charge air pressure sensor -G31-
Checking -G31- Page 21-63
22 - Throttle valve control module -J338-
23 - Recirculating valve for turbocharger -N249-
Checking Page 21-45
24 - Intake manifold
With Intake Air Temperature (IAT) sensor -G42-
25 - Pressure unit
For wastegate
26 - Wastegate bypass regulator valve -N75-
Checking Page 21-57
27 - Mechanical recirculation valve
Checking Page 21-43
28 - Pressure control valve for crankcase ventilation
29 - Secondary Air Injection (AIR) pump motor -V101-

[Monster Stealth]

Thanks that help a ton, hopefully when this is all said and done I can have a writeup and give a small review on the effects of krank vents on our engines

[Monster Stealth]

Ok, what is the difference between #1 and #9 on the AEB diagram? If I understand it correct #9 is the actual PCV valve, and #1 acts as a restrictor to minimize oil and sludge from entering the TIP? If I am correct, I plan on running a catch can directly off the exit of #1 from TIP and eliminating it completely. Off the catch can I would run one krank vent to the valve cover. Icould eliminate the hard line going back around the engine that tees in with #9. Then I could run a krank vent from #9 to the intake manifold. What do you guys think?



Like this

[TQMB5]

i guess i will post this question on here since it is relevent, but your those of your who removed your combi valve from the back of the head, What did you do with the vac link on their? It runs to under the intake mani.

[Monster Stealth]

Does the AEB valve cover have a breather port? I dont see one on any pics I am seeing

[djwimbo]

the AEB doesn't have a breather port on the valve cover. In the photo fo the vacuum diagram the actual PCV valve is just above the #9. It is the "T" at the intersection of the 3 lines there. The one is manifold vacuum, another is the crankcase pickup and the third goes to the pancake valve. The pancake valve is a metering device that only allows a certain amount of PCV gases to be recirculated. The PCV is boost referenced b/c they obviously don't want straight boost going into the crankcase. So there's a check valve there too, in the PCV.

[Monster Stealth]

the AEB doesn't have a breather port on the valve cover. In the photo fo the vacuum diagram the actual PCV valve is just above the #9. It is the "T" at the intersection of the 3 lines there. The one is manifold vacuum, another is the crankcase pickup and the third goes to the pancake valve. The pancake valve is a metering device that only allows a certain amount of PCV gases to be recirculated. The PCV is boost referenced b/c they obviously don't want straight boost going into the crankcase. So there's a check valve there too, in the PCV.

So where exactly does the excess crankcase pressure come from, what port exactly. The only things I see connected to that line is the vacuum from the manifold to the TIP. I was under the impression PCV valves vented preassure from the crankcase, but I am not seeing it here. Sorry if I am making this too difficult

[317ssayzarc]

So where exactly does the excess crankcase pressure come from, what port exactly. The only things I see connected to that line is the vacuum from the manifold to the TIP. I was under the impression PCV valves vented preassure from the crankcase, but I am not seeing it here. Sorry if I am making this too difficult

#9 on the AEB chart is the crankcase port, it bolts to the block

[Monster Stealth]

Sweet, thanks for the quick reply, I shouldn't have any problems hooking up my krank vents then, but I will have to tee off that #9 port like it is from the factory

[317ssayzarc]

Sweet, thanks for the quick reply, I shouldn't have any problems hooking up my krank vents then, but I will have to tee off that #9 port like it is from the factory

whats a krank lol?

check out the 034 breather port adaptor, i run it on my audi and it greatly reduces the work needed to redo the pcv system

[timjadams]

Does the ATW have a PCV valve? I was sold one.....

[djwimbo]

Does the ATW have a PCV valve? I was sold one.....

All cars from IIRC '67 and up have a PCV system.
So, Yes, it does.