Volkswagen TDI ALH Vacuum Diagrams (Stock & Modified)

I'm glad that ^ that guy brought this thread up...I had a loose hose and was able to get it routed properly.

Thanks!!

lol, that's great for you but I still don't have an answer....

Glad I could help someone.

suscribed

Hey guys,
Sorry to be a noob, but thanks for the awesome diagrams. I have one question. I just did the EGR delete and on the Diagram im confused on where to put the vactuam hose for #3 on the diagram. I dont know where that vacuum hose goes to. All help is appreciated and thanks in advance.

Mbyrne455 said:

Hey guys,
Sorry to be a noob, but thanks for the awesome diagrams. I have one question. I just did the EGR delete and on the Diagram im confused on where to put the vactuam hose for #3 on the diagram. I dont know where that vacuum hose goes to. All help is appreciated and thanks in advance.

Click to expand...

Hose #3 follows the plastic intake piping down to the turbocharger and gets plugged into the bottom of the VNT actuator. If you put a golf tee into it and plug it then you will get very little boost (low power).

Mbyrne455 said:

Hey guys,
Sorry to be a noob, but thanks for the awesome diagrams. I have one question. I just did the EGR delete and on the Diagram im confused on where to put the vactuam hose for #3 on the diagram. I dont know where that vacuum hose goes to. All help is appreciated and thanks in advance.

Click to expand...

Another member of the Sewcyetty Four Kreaytive spelling…

Gregg622 said:

lol, that's great for you but I still don't have an answer.....

Click to expand...

I removed my N18 from the car and tie wrapped the cable out of the way.

This then threw a fault code so I replaced the N18, reconnected the wiring plug and connected all of the hoses together with the aid of a T piece so there are no open hoses and no air getting to the N18 and now it doesn't throw a code...


The other advantage in doing this is that should the N75 decide to fail at any stage on a journey, I have a spare already to be fitted under the bonnet attached to the boost/inlet hosing! (N18 is the same item!)

FF

So here's a question is there any negative side effects by unplugging the vac lines to the egr and the asv? Reason I ask is my 01 alh doesn't have a asv and yes I know what it is where it is etc.. so always had 1 line blocked off and the egr I just unplugged and blocked and haven't noticed any adverse effects except more power and better responce so is this harming anything? And note I do not have a cel on

strange, this thread attracted a LOT of noobs towards the end..................

suscribed

Ok I had to replace my Turbo. About 3 sec. after first start up ASV valve went shut. I removed the wire from the n239 valve for a temporary fix so I could drive the car. Long term though I would like to get it fixed. with engine running If I plug the wires back on the N239 the ASV goes shut and kills the engine. This makes me think the N239 is working. But for some reason its getting a signal to close when it shouldn't. I have checked the wires back to the firewall and cant see any problem. Does anyone have any idea whats going on
Thanks in advance

backwards hoses on the ASV could cause u'r symptoms...

cody1cody said:

Ok I had to replace my Turbo. About 3 sec. after first start up ASV valve went shut. I removed the wire from the n239 valve for a temporary fix so I could drive the car. Long term though I would like to get it fixed. with engine running If I plug the wires back on the N239 the ASV goes shut and kills the engine. This makes me think the N239 is working. But for some reason its getting a signal to close when it shouldn't. I have checked the wires back to the firewall and cant see any problem. Does anyone have any idea whats going on
Thanks in advance

Click to expand...

make sure the two hoses on the automatic shut off valve are in the correct order.

Having those two hoses backwards will give one of two outcomes, either you will have no boost whatsoever if the valve is leaking vacuum or the ASV will immediately shut killing the engine...

I have seen both of things happen after a turbo replacement,,,,....

And make sure you did not plug the ASV solenoid into the crankcase vent heater plug...check the wire colors with the manual.

Thank Guys .
DanG144
I did have it and the Crank Case vent heater connectors crossed.

I bought my car with the ASV hoses switched, and it had low boost, as rotarykid mentioned as a possibility.

Even with only two ports on the valve, there is a third port hiding under a dust cap. If the hoses are reversed, the vent is dumping system vacuum overboard, leading to no vacuum to drive the boost actuator.

So today I replaced most of the vacuum lines (Mk IV ALH), with much thanks to the diagrams and other previous posts in this and other threads. I ran into a few concerns:

1) The vacuum line running to the small actuator near the EGR will not come out, and has started to tear in the attempt to remove it. Is it attached any differently than other lines? If the line tears any more, there won't be much remaining to tug on for removal.

2) The only other obvious line that I did not replace is the one that (I believe) runs down to the turbo actuator (it's the longest of the smaller diameter hoses, and runs down behind the block). Does this have to be accessed from below for replacement?

3) Unless I missed something (which is entirely possible), is it normal to have quite a bit of vacuum hose remaining? I have the pre-cut kit from ID Parts, and have over 3 feet of larger diameter left, and 4' 9"of smaller diameter remaining. I didn't measure them at the start, but it should have been 3m of 3mm, and 1m of 5mm hose.

4) Given how brittle some of the plastic vacuum line connectors seem to be, shouldn't all of these be replaced when doing the vacuum hoses?

5) The braided cloth lines near the fuel injectors look similar, but I'm guessing the vacuum hose is not an appropriate replacement? One of mine shows a small amount of fuel near the end.

6) Can loss of FE be attributed to vacuum leaks, or do vacuum leaks mostly contribute to codes and turbo issues? I have good power, no codes, but slightly lower FE since spring.

TIA!

There was a post floating around some years ago, with appropriate diameter replacement hoses for both vacuum and fuel-return. I think the fuel-return hoses were made of viton, and the vacuum hoses were silicone? In any case; I did this procedure on my 2003 (ALH) in about 2005. The condition of the stock vacuum hoses was TERRIBLE. What a ****ty choice of materials by VW. My son drives this car now, and when I check the hoses, they're still good as new; soft, and flexible, and they still hold vacuum well. So I highly recommend this replacement job. Before this job this car ran like crap, and I was getting codes all over the place, and my N75 failed. I think that the crappy vacuum led to a VW mechanic at the dealer (the ONE time I trusted them with my car), to mis-adjust the turbo actuator, so that once I replaced the vacuum line and N75 myself, I was getting limp mode all the time, and I ended up having to re-adjust the actuator myself. (a learning experience).

Ok, so I solved number (1), from my post above (#76). For anyone who finds this through a search: The previous techniques of slicing the tube near the nipple to ease it off, or using a tiny bit of solvent to break the bond were both not working. I ended up cutting the tube where it was starting to tear, and using small sharp scissors to cut downwards towards the nipple. The plastic at the base of the actuator prevented me from getting all the way down, but I was able to eventually wiggle it off.

Any other input is appreciated.

For number (5), I see IDParts sells hoses just for the lines from the pump to the injectors (these are fuel return lines?), so they must be fuel-rated.

need4: Thanks for the input. I've checked out a lot of the silicone hose threads, but had already bought the OE replacement hoses for vacuum. Plus, I'm not a big fan of how the silicone look (and in some applications seem to react to fluids or get soft and collapse inwards). Maybe next time. My OE lasted 13 years, so not too bad.

Today I had the Golf up on the lift to finish replacing the vacuum hoses. To answer numbers (2) and (3) in my post above, I replaced the turbo actuator vacuum line from below, and would not have been able to do it from above unless there was no clip (still had the original VW metal band on it at the actuator nipple), and if I wanted to ignore the hold-down routing, which I could only reach from below. I still have a lot of larger ID hose left, but now only about a foot of smaller hose remaining.

port sizes are approximate

EGR valve problem P0401 fault

Wow thanks for this. I'm new to this group, really like all the info.
I have a clapped out 2003 Jetta TDI.
I was getting an error code P0401 indicating an EGR valve problem.
I know all the carbon build up plugs the EGR and intake manifold, but I'm not skilled enough to do this myself...yet. I did find a ball bearing jammed in the EGR valve hose?! I cut the hose back, removed the ball bearing and the P0401 fault went away, go figure...

Just used this for vacuum routing on my EGR and ASV deleted ALH Jetta... thanks a bunch OP!!

atownbrg said:

port sizes are approximate

Click to expand...

Thanks for this. I was wondering how the line going to the air box played a part. I am putting an EGR/ASV deleted ALH in a Mk1 and I also can't fit the factory Mk4 airbox so I was looking for a few solutions.

Thanks to all contributors!

I think this diagram came from someone on this site,not sure who though.
edit:Old No7

Thank you !

DaveLinger said:

After using aNUT's very helpful thread to help me re-do my vacuum lines, I decided to re-make his diagrams into more complete, readable, printable, noob-friendly forms. I used his diagrams in combination with TonyJetta's labels. They're color coded so that you don't start looking at one and accidentally look at a different one next time you take a glance. I named the thread very verbosely to hopefully have this thread come up when such a topic is googled.

Here are vacuum diagrams for a stock ALH, ALH with EGR delete, and ALH with EGR and ASV delete.

Images are thumbnails. Click for full-size.



Of course it goes without saying that although these are the "shortest" paths, these are not the only options. Please let me know if I missed something or messed something up.

Click to expand...

excellent diagrams especially with asv and egr gone as on my motor.

Well I lose power when I remove the N239 and N18??? I have an EGR DELETE on my 02 vw jetta TDI.......

Hugh86 said:

Well I lose power when I remove the N239 and N18??? I have an EGR DELETE on my 02 vw jetta TDI.......

Click to expand...

If you are using a 'racepipe', i.e. no ASV, then remove 'em and plug any loose hoses.

flee said:

If you are using a 'racepipe', i.e. no ASV, then remove 'em and plug any loose hoses.

Click to expand...

what do we plug the hoses with??

Im working on getting my car back to 110% and am recognizing that i have an N75 and N18 Plummed in, i guess like the center diagram if i compared the two. So, I think i will simplify it, because i am running the Race Pipe, ASV/EGR are gone, and have been by Previous owner, in 2011.

To merely plug the unattached hoses any small obstruction (golf tee, etc.) will suffice.
In your deleted situation, the third diagram would be the simplest one to follow.

DaveLinger said:

After using aNUT's very helpful thread to help me re-do my vacuum lines, I decided to re-make his diagrams into more complete, readable, printable, noob-friendly forms. I used his diagrams in combination with TonyJetta's labels. They're color coded so that you don't start looking at one and accidentally look at a different one next time you take a glance. I named the thread very verbosely to hopefully have this thread come up when such a topic is googled.

Here are vacuum diagrams for a stock ALH, ALH with EGR delete, and ALH with EGR and ASV delete.

Images are thumbnails. Click for full-size.



Of course it goes without saying that although these are the "shortest" paths, these are not the only options. Please let me know if I missed something or messed something up.

Click to expand...

Is this good scheme for awx/avf motors?