Volkswagen TDI ALH Vacuum Diagrams (Stock & Modified)

[DaveLinger]

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.

 

[MrBigTruck]

On the diagram with the EGR and ASV removed, would it clean things up to delete the vac reservoir too? I'm pretty sure it is only used for the ASV. That would clean things up even more. I'm not totally sure about that but I think I'm gonna give it a try.

 

[Milage King]

N75 that controls your turbo runs on vacuum, but more importantly your BRAKES.

 

[MrBigTruck]

The brakes and the N75 are hooked directly (more or less) to the vacuum pump. I was referring to the vacuum reservoir. I think, though I'm not totally sure, that it is only used for the N18 and N239 operation. Diagram 3 has no N18 or N239 so it wouldn't need a reservoir if my theory is correct. Does anyone know for sure?

 

[2000jettaglstdi]

I have a 2000 jetta tdi i just removed the Asv and it would seem I broke the vacuum actualor, is the turbo still gonna spool okay or did i kinda screw myself over?

 

[DanG144]

You broke the plastic vacuum actuator on the ASV? Or the Turbo metal vacuum actuator?

 

[2000jettaglstdi]

just the plastic one, i figured it just opens and closes the plate that (no longer) blocks the air from the manifold. am i right to assume that?

 

[DanG144]

You are correct in what it does, but I suspect you are a bit unclear on WHEN it does it.

First, if you just block off the vacuum hose to the broken unit (or you can leave it on as long as the break is the common linkage break, which will not impact the vacuum system), then it will not impact turbo operation at all. Ensure the ASV butterfly is fixed in the OPEN position - by string, tape, tywrap, or its own spring - if the linkage is what is broken. Note that several have repaired their ASV linkages with lasting success - though the threads may be hard to find.

The ASV is only moved in two cases. Otherwise it is fully OPEN on a diesel engine.
Case one - every time you shutdown the engine, to prevent a shuddering stop.
Case two - when the EGR valve throttles, gets almost closed and still needs to reduce fresh air intake. This is a very rarely needed feature, and losing it will not impact engine operation at all.

While many people completely remove the ASV, I like to keep it functional, as it is a possible defense for a runaway engine.

 

[2000jettaglstdi]

Okay, well im glad you cleared that up, i took the whole butterly off.

 

[ALIKA]

EGR delete

Hello there!


I've found this thread thanks to a Google search.

It's actually the only one I could find talking about ALH engine,but the diagram on the UK forum about PD engines is actually helpful too.

http://translate.google.fr/translat...s.net/forums/t/393238.aspx?PageIndex=1&anno=2

Anyway,I'd like to participate to that EGR N18 and ASV N239 delete,since I'm in the middle of it right now.

I have a 2002 Jetta TDI ALH engine that I bought with a stripped timing belt.I never touched a TDI before (super noob) (just a M-TDI 1Z and other 1.6 and 1.9 D and Td)

I repaired the damages ( only 1 valve bent and miscellaneous stuff)

During the work,I thrown away a box with a couple things by mistake,and there was the N239 in one of them....

Engine purrs even with the timing done with no special tools ( timing belt tools are a joke,you can totally do without the ALH specific tools by the way),I dialed with a gauge at 0.98 for now,I will correct timing with a friend + Vag com)

I did a block off job on the engine,to get rid of the EGR bull****


I used a VAG block off plate to stay VW original

I would like to get rid of the N239:

>> nobody says how to measure the resistance on the connector:engine off,ignition ON but engine OFF,engine running,or engine running then turned OFF and read immediately after that? The last one seems to me the one that will work,since the info is given by the computer to close the ASV at this moment. But if somebody could tell how to do it,it will same me and other members some time
>>> I'll have to remove the flapper inside the EGR valve or block it open,correct?


I would like to get rid of the N18:

>> same thing,when to measure resistance between pins in the connector?
Also,I'm keeping the EGR valve but with a block off plate.

Option one:keeping the N18 :some people put a ball bearing to clog the vaccum tube: is it necessary if the EGR has a block off plate?I'm confused.I would say NO,no need,but please tell me.

Option two: deleting N18:remove vacuum tubing as necessary and put a resistor in the connector:that's all?

Thank you guys!!

Alex

 

[Corsair]

Sorry for going off topic with #10, but...

I have a 2002 Jetta TDI ALH engine that I bought with a stripped timing belt.I never touched a TDI before (super noob) (just a M-TDI 1Z and other 1.6 and 1.9 D and Td)

I repaired the damages ( only 1 valve bent and miscellaneous stuff)

Very often when a TB failure occurs, damage exists in valves and / or followers that is not visible. It exists in the form of small stress fractures that will result in a failure down the road. Sometimes it's just shortly down the road, other times the engine can run for thousands of miles before "the event" happens. Typically "the event" consists of a valve breaking or follower failing while the engine is running. In addition to a stripped timing belt (again), the potential exists to encounter significant impact damage from loose bits getting crunched in at least one cylinder. (There was another post on here recently, with pics of such an event).

If the car was obtained with a failed TB, and the cylinder head was not completely renovated as part of the repair, you may want to think seriously about taking the car out of service, removing the head and having it totally renovated. I understand you're in HI and may have to ship very long distance or local parts / services unusually expensive. Sorry for that. Otherwise, it remains a roulette game each time the engine is fired...

[edit] Thanks to OP, by the way, for posting the GREAT different stage vac diagrams.

 

[Lefty]

Sweet, Just planed on redoing my lines soon and would like some help if I get in trouble with it.

 

[PRA4WX]

The brakes and the N75 are hooked directly (more or less) to the vacuum pump. I was referring to the vacuum reservoir. I think, though I'm not totally sure, that it is only used for the N18 and N239 operation. Diagram 3 has no N18 or N239 so it wouldn't need a reservoir if my theory is correct. Does anyone know for sure?

Curious as to what the purpose of the reservoir would be in that scenario myself......?

 

[DanG144]

The reservoir will hold vacuum, and smooth out vacuum changes, for the N75 turbo operator. I would leave it.

 

[Canadian_Grizzly]

The reservoir will hold vacuum, and smooth out vacuum changes, for the N75 turbo operator. I would leave it.

...and the braking system. Without reserve air a couple hard brake applications and then rock solid brake pedal. I'm of the opinion to leave things as stock as possible.

Nice diagrams BTW.

 

[ALIKA]

Aloha people!

to answer questions and concerns:

I bought the car for parts,at 500 bucks,I couldn't go wrong.....

I opened the engine,and oh my,there was nothing almost.

The tow guy who sold it to me told me they broke the timing belt trying to start the car. I didn't believe as a principle,people (like mechanics) often lie about that to minimize concerns.

In fact he was true,the car has been sitting for a year almost being towed from one dealer to another one for estimates.I ended up with a missing downpipe and a couple thingies this and there,not a big deal after having completed the giant puzzle out of a big box of hardware and parts that have been removed.Just the head had been put back on the block.
The timing was stripped a little bit,I got 3 dead glow plugs and one very weak also.
Injection pump was leaking badly as well etc....
So I guess it was true,looking at the damages:barely bent valve,slightly f...ked cam follower,even the pistons had nothing,I could barely see where it hit.So I won't be scared about it.That really was good luck for me.


After years of working on old VW diesel engines,I'm not scared of anything now

As for the vaccum reservoir,I've read it's used just for the N239 when you shut off engine.It doesn't impact the brakes since the brake booster got its vacuum from the main line from the vacuum pump.Circuit needs to be closed properly of course.

The N75 is for the turbo wastegate I've read also,so nothing to do with the reservoir since the vacuum is generated by the vacuum pump when engine is running,no need big vacuum reserve at once.At least what I've read make sense to me.

Does anybody have input about my previous message?

Good night

 

[DanG144]

Typically any valve that has impacted a piston should be replaced. If not, the head will break off of the impacted valve, usually about 10 or 12 kmiles later.

While the engine will run without the reservoir (and I agree the reservoir does not support the brakes - it is isolated from the brakes and the other controls by a check valve) the reservoir does provide a surge volume for the N75 turbo controls, to help ensure smoother operation. I have seen people take it off, and run without it, and the engine will run. I have no ideal of the impact on the turbo controls.

VW spent money on installing the reservoir for a reason.

We have seen literally dozens of folks make the same assumptions you have about the valves after a TB break. Too many times the engine fails 10k miles later.

Good luck.

 

[OptimusFuel]

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.

What about for BEW? is this the same or is it different? would like to know all 3 ways as well for the BEW.

 

[ALIKA]

Hello!

let's focus on the topic please

(I replaced the bent valve that hit,others didn't hit at all )

 

[loganbmx4gt]

Hello!

let's focus on the topic please

(I replaced the bent valve that hit,others didn't hit at all )

What exactly would that be....?

 

[steven11chester]

I know this is an old thread, but is the #7 check valve the one between the 2 BIG black hoses? and i mean like half inch hoses with a small nylon one coming off??? If so i broke the little nipple off... any suggestions?

 

[runonbeer]

buy a new booster line. 1J0612041GD

about $45. It's eventually going to break in other places anyway. I replace a lot of these.

I know this is an old thread, but is the #7 check valve the one between the 2 BIG black hoses? and i mean like half inch hoses with a small nylon one coming off??? If so i broke the little nipple off... any suggestions?

 

[Seatman]

Lol at this thread, it started well but went a bit skewed

 

[Seatman]

Thanks for the diagrams Dave, just did the egrless one on my car with some lovely blue silicone piping.

 

[vlad0401]

I need to replace all my lines in diagram one. Is there a kit to change all of them? If not I'd like to just have the required amount of hosing to replace them all. I just had to replace my vacuum one because it cracked and all my other ones are in bad condition. If someone could give me a link because I'm not confident in finding it myself. Thank you

Edit: Just read the post above me, I wouldn't mind colorful ones either. Blue one or even clear ones are nice. Any will do though, as long as it does the job.

 

[runonbeer]

Post #19 has a link to some good silicone stuff. And some other posts vaguely show how to get to all the lines at once.

http://forums.tdiclub.com/showthread.php?t=356217&highlight=Vacuum+vice&page=2

 

[NarfBLAST]

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.



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.

Thanks Dave! A great job on those diagrams, sorry your thread got completely hijacked! Here is my interpretation of an ALH with EGR removed in orange silicone vacuum hose:

 

[Seatman]

Thanks Dave! A great job on those diagrams, sorry your thread got completely hijacked! Here is my interpretation of an ALH with EGR removed in orange silicone vacuum hose:

Dude! Get cleaning lol

Yes I opted for blue

 

[NarfBLAST]

Dude! Get cleaning lol

Very nice, but you missed a spot on the underside of your dip stick tube.

 

[Birdman]

The brakes and the N75 are hooked directly (more or less) to the vacuum pump. I was referring to the vacuum reservoir. I think, though I'm not totally sure, that it is only used for the N18 and N239 operation. Diagram 3 has no N18 or N239 so it wouldn't need a reservoir if my theory is correct. Does anyone know for sure?

You could remove the reservoir but you would lose any backup vacuum to operate the brakes if your engine suddenly stopped running. and if like my car which has the EGR deleted and has had the EGR / ASV valve gutted out and smoothed out inside so it now replaces the race pipe but with the ASV still working to shut the engine down, when you turn the car off and also when needed to help stop a run-away engine. You can always move the reservoir to a better spot if you need to.