[TRespect]

I did this job and wanted to share some pics.
The Treg had developed a serious coolant leak on the passenger side bank (LHD). But the leak was not visible outside or underneath the car. Coolant was leaking on the aluminum coolant return line and evaporated leaving only limescale traces on the return line. I had to remove the intake valve to find out.
The leak was due to the previous owner(s) using tap water I guess as the the pressure was pushing all that accumulated limescale out causing the hose to bulge at the combi valve port. The clamp crumbled to pieces when I removed it.
I replaced the combi valve too. I got a used one for a few euros. Tested good with a vacuum pump. I also replaced the hose coming from the V55 secondary pump. This hose is not sold separately by VW. It is connected to another hose (moulded) going to the coolant expansion tank. I got one on ebay. It came from a 3.2 Porsche Cayenne.

Before:

 

[TRespect]

Removal:

 

[TRespect]

The moulded hose connection:

View attachment 239930

 

[TRespect]

After:

 

[TRespect]

How all this wired up:

Secondary Air System where the combi valve is used:

secondary air pump Touareg (TOUA) 2004 year Volkswagen EUROPA 131005

secondary air pump Touareg (TOUA) 2004 year Volkswagen EUROPA 131005 spare parts

volkswagen.7zap.com

 

[TRespect]

Hose coming from the secondary pump and going to the engine block through the egr mount:
Hose number 7

coolant cooling system; auxiliary heater for coola... Touareg (TOUA) 2004 year Volkswagen EUROPA 121037

coolant cooling system<br/>auxiliary heater for coolant circuit<br/>for model with electronically regulated air conditioner, second evaporator and second heater in rear<br/>see illustration: Touareg (TOUA) 2004 year Volkswagen EUROPA 121037 spare parts

volkswagen.7zap.com

 

[TommiT]

You can't beat pictures!

 

[TRespect]

Absolutely

 

[Hampton52]

Nice ... Thanks for the photos and diagrams.

 

[TRespect]

You’re welcome.
Next step is a coolant system flush/clean. I’m tempted to use a cleaning product even though I don’t like introducing ´magic’ products into the system. I do want to remove all what the tap water has deposited in the cooling system. Maybe a few G13 flushes with distilled water will do the trick.


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[black_orion]

You’re welcome.
Next step is a coolant system flush/clean. I’m tempted to use a cleaning product even though I don’t like introducing ´magic’ products into the system. I do want to remove all what the tap water has deposited in the cooling system. Maybe a few G13 flushes with distilled water will do the trick.


Sent from my iPhone using Tapatalk

Hi, after you've taken the combi valve off, did you notice any carbon build up in the air's passage? I don't have any colant leak, but will be changing the combi valve, and I'm thinking to do it without taking the whole assembly off, I want to do only the combi valve, but was wondering if the air's passage have some blockage, than the whole work would be a waste of time. Thanks

 

[TRespect]

No carbon buildup. You can test the valve without removing anything. Just make sure the 4mm hose is not cracked behind the engine. I relocated the solenoids and vacuum tank like I explained in other threads. Makes it easy to work with the solenoids and troubleshoot the system. I really advise you to do so.
Here is how to test the combi valve:

Get 1 5meters 4mm hose and replace all the vac hoses. Here is how another forum member did it:

Engine banks 1&2 running lean ‘04 V6

I’ve replaced the MAF and now I’m about to replace hoses. The Treg is malfunctioning due to snapped hoses.

www.clubtouareg.com

And that's exactly how I did it a while bac:

3.2 Valve cover gasket replacement

Some updates here: Got some answers about the bulging intake and the puffing sound. Vr6 owners say it's normal. So this settles is the engine sound issue. I did a tear down of the pcv and now I understand better how it works and why it spurts out pressure from the nipple/barb whole. Some pics...

www.clubtouareg.com

 

[TRespect]

What errors are you seeing in VCDS?

 

[black_orion]

Hi I inspected the secondary air injection lines, no cracks at all. I still get the code P1411 insufficient flow.
I had the codes before:
P1411, P0430 and P0420 and multiple misfires.
I changed the spark plugs, an ignition coils, new cover and cylinder gaskets , MAF sensor and PCV. Also got the catalytic converter changed with the aftermarket one, kept the old original one tho just in case, but the honeycombs are in bad shape, they look deformed.
I'm still getting the P1411 insufficient flow. Changed the SMOG pump relay, the fuses are ok.
I'm waiting the new combi valve to come first so I can install the SMOG pump too. The only thing are those secondary air injection solenoids, 2 of them 1J 906 283 B. They use 12V to trigger combi valve. Not sure if they could be a problem. I will test them first. And yes, all those hoses from the air filter housing to the SMOG pump, and from the pump to the combi valve have been changed too.
And after all this I still love my Touareg hehe

 

[TRespect]

Get the solenoids and the tank out of the there and route them with new 4 mm hoses. They are cheap. Ditch the hard plastic stuff if not already done. It's not that complicated. you can trigger the solenoids closed or open using a connector so you don't short stuff. You can use the battery posts in the engine bay to trigger the solenoids. And get a vac pump on amazon if you want to test the hoses too. Just tear the whole vac hoses out and I can help you re-route them. Trust me it will be easier to work with in the future.
You can swap solenoids or completely block one of them once you know how they work. One solenoid is for the variable shifter rod in the manifold. The other is for the combi valve. They are the same.
So To test the flow:
Pull the hard plastic hose going from the secondary injection pump to the the metal hose on the left side of the engine (left side when facing the car from front). Connect a rubber hose to the metal hose. Blow into the rubber hose and see if you have air coming out the exhaust. See the video above if you want to put gloves on the exhaust tips to see if they inflate.
With engine off you don't have air coming out eh exhaust. This means the solenoid is not open and vacuum is not pulling on the combi valve diaphragm.
To test flow you need a pump to pull vac at the combi valve. If you trigger the solenoid with a 12v source (or maybe 5v/9v) the solenoid will let vac through but with engine shut you need a hand pump.
If you relocate the solenoids you can just unlplug the hose going from the combi valve and plug it into the hand pump and let the pump open the combi valve then blow into the rubber hose gong to the combi valve from the secondary injection pump.
So you have multiple points of failure:
Combi valve
Solenoids
Hoses
Seconday air injection pump which might also not be sending any fresh air throught the combi valve. You can test the pump too. Unplug the hose going from the pump and start the engine when it's cold.
Let me know if you need help relocating those hoses and wires. You need about 4-5 meters of 4mm silicone hose. 4-6 meters of some 24 awg wire (red and black) to extend the solenoid wires. Take pics before removing and mark which wires go where. If you mess up I can help with that.

 

[black_orion]

Thanks a lot for the direction you gave me. Are those solenoids, 2 of them, known as N112 and N156?
I will be using vac hand pump. After I've read 1 article, I could say that my problem 90% is the bad pump.

6 Symptoms of a Bad Secondary Air Injection Pump & Replacement Cost | Complete Car

I was on my way to work when I noticed that my secondary air injection pump was bad. I didn’t...

completecar.ca

I have had all those symptoms, specially on traffic lights.
I will post the results, just waiting the combi valve to come, I want to install it first along with the solenoids, and the last will be the pump, because the reverse order would bring the pump failure again.
I also bought 4mm vacuum hose to replace, but tbh I'm not just confident to reallocate everything as the work with the electrical cables is involved to get them extended.

 

[TRespect]

I'm confident you can do it. It's pretty easy. Two wires for solenoids. Mark the wires, cut, solder the new extension wires and cut when you have are happy with the extension. Just leave some wire length for any future work. As for the hoses just tear them all off. Here is what you have down there in that super heated environment:
Two solenoids => same part 1J0906283B => They have a different name 112 operates the combi valve. 156 operates the variable intake manifold shifter rod. But they are the same part number. Even if you swap them around you won't have an issue. You just need to wire them correctly.
Vac tank.
Crumbling hoses: either the visible part of the hard plastic hoses or the hidden one. The hoses go into a protection hose. They ight be broken or cracked inside that protection behind the engine. There is a lot of heat there.
Here is what you are going to remove:
Follow the hose coming from the intake manifold and going to the solenoid/tank and remove it
Follow the hose coming from the combi valve and going to the solenoid/tank and remove it
These two hoses will be joined together in a protection hose.
Unscrew the tank/solenoid support and remove it.
Disconnect the hose from the intake manifold valve.
Extend the wires using solder and hear shrink. You can use the cold soldering heat shrink stuff I put in one of my thread.
Find a good spot to install the tank and solenoid behind the driver side headlight. Use some zip ties to make a firm fix and not leave the tank and solenoids tapping against the treg body.
How is everything wired:

Vaccum is at the intake manifold => goes through both solenoids to the combi valve and the shifter rod arm. Vaccum is let through with the solenoids opening or closing (by the ecu).
There is a check valve to help with using the vacuum tank when you don't have vaccuum at the intake manifold (high engine load. vaccum is more important at idle).
Now you have a clean setup and you are 100% your hoses and good. And you can perform you diagnostics at ease. Get a spare connector online or from a junkyard and use it to work with the solenoids using the battery posts in the engine bay.
You can even check if the tank is not cracked too.
Send me a pm with your number and I can help with this.
You can test the pump easily. Let the Treg cool down. I mean do the test in the morning or after the treg has been sitting cold for a few hours:
Disconnect the hose coming from the pump and going to the metallic tube on the engine left side (while facing the engine from the front). You will feel the pump blowing fresh air for 90 seconds I think. And you will hear it running under the left side (or passenger side for a LHD) headlight. I'm adding some pics of the setup so you get the idea.
System is easy to diagnose once you know how it is wired.
You can monitor when it is activated in vcds too. They system is used when car is cold and is also tested several times when car is driving or idling. The ECu activates the pump and expects a burst in air which in turn makes the fuel/air mixture lean. If the expected lean fuel trim is not reached the system generates the error code of insufficient flow.
So either your leads are:
Pump does not generate fresh air
Vacuum hose is split at any spot between the intake manifold port near the PCV and the combi valve (going through the solenoid.
Solenoid is broken and does not open when required by ecu => vacuum not pulling at the combi valve.
Combi valve diaphragm is torn or combi valve is clogged and air coming from the pump is not allowed through the combi valve.
All this is mechanical stuff and can be tested with a vacuum hand pump and blowing air through the system or triggering the pump to run. But even that is not needed.
And of course there can be other issues.
If you're not confident with wiring just take it to an electric shop and ask them to rewire it for you. This is for me a very critical step to fixing and SAI (secondary Air Injection) issues on the 3.2 Treg.

 

[TRespect]

The blue hose is the primary vacuum source for the SAI. Follow this one and it will lead you to the rest of the system components:

 

[TRespect]

Diagrams of both SAI and Intake parts:

 

[black_orion]

I pulled out the hoses and now I'm changing the vacuum lines with the new Gates vac hoses. Did you keep any of those little hoses close to the vac reservoir? How did you change the forked hose? I need to pull out the hose which goes into the vac reservoir, but now I'm no t sure how it is connected inside. I tested the solenoids with the 9V battery and they work as they should. I found a silicon hose crack close to the combi valve.