Complete Vacuum Diagram for Jetta TDI 1998

[GiGGer]

I am looking for the complete vacuum diagram. according to Mitchell OnDemand, i'm plugged correctly as for the N75 valve but my actual boost has problems reaching the specified boost, which will cause limp mode on 5th gear.

Thanks

 

[P2B]

 

[euromade]

would this work on a 96 passat? or better yet do you have one of these diagrams for my passat?

 

[GiGGer]

Should be the same for the Passat.

 

[GiGGer]

That is a very nice picture, many thanks!

 

[wndboy]

is this the same diagram for a VW 1998 jetta TDI? I just had my engine rebuilt and we are having problems figuring out the vacuum lines.

Thanks,

 

[TonyJetta]

is this the same diagram for a VW 1998 jetta TDI? I just had my engine rebuilt and we are having problems figuring out the vacuum lines.

Thanks,

1998 or 1998.5?

The early is an AHU; Later is and ALH

This diagram should be fine for the AHU.

Tony

 

[wndboy]

1998 or 1998.5?

The early is an AHU; Later is and ALH

This diagram should be fine for the AHU.

Tony

Not sure what engine I have. What is the difference between the AHU and the ALH? How do I tell which one I have? If I have the ALH engine, does anyone have the diagram or schematic for this one?
Thanks again,

wndboy

 

[TonyJetta]

What is the difference between the AHU and the ALH?

There are several subtle differences. Motor mounts, vacuum pump, injection pump, and many others that I am not aware of.

How do I tell which one I have?

Look on the timing belt cover; see the barcode? Also, the ALH intake manifold points to the Passengers side (like this pic); AHU/1Z points to the drivers side.

If I have the ALH engine, does anyone have the diagram or schematic for this one?

 

[P2B]

1998 or 1998.5?

The early is an AHU; Later is and ALH

This diagram should be fine for the AHU.

Tony

The AHU to ALH changeover occured in 1999 for Jettas - 1999 Jetta was Mk3 body AHU motor and 1999.5 was Mk4 ALH.

Simon

 

[TonyJetta]

Simon,
Thanks for setting me straight!

Tony

 

[Chubber]

That is great. I am printing it out and sticking it in the owners manual.

 

[wndboy]

Still having issues trying to figure out my vacuum lines. Vacuum diagrams posted here have helped but does not list all vacuum hoses for this engine. In question is this part that is located on the right bottom side of engine (AHU) 1998 TDI, right next to manual transmission. One large black hose goes from this part to the brake master cylinider. Within this large black hose their is a small black plastic piece with 2 tits where two vacuum hoses go. One of the vacuum hoses is attached to a short black piece of vaccum hose and connects to a green plastic hose and runs to another short piece of vacuum hose that connects to another black plastic piece with 2 tits and an electrical connection at the right side of the fire wall (Just left of the raidiator reservour) Is this connection right? Where does the other vacuum hose comming from the first black piece on the brake master cylinder hose go?
**I realize this is long and drawn out but I tried to be as descriptive as possible. Thanks

 

[P2B]

Still having issues trying to figure out my vacuum lines. Vacuum diagrams posted here have helped but does not list all vacuum hoses for this engine. In question is this part that is located on the right bottom side of engine (AHU) 1998 TDI, right next to manual transmission.

That is the vacuum pump.

One large black hose goes from this part to the brake master cylinider. Within this large black hose their is a small black plastic piece with 2 tits where two vacuum hoses go. One of the vacuum hoses is attached to a short black piece of vaccum hose and connects to a green plastic hose and runs to another short piece of vacuum hose that connects to another black plastic piece with 2 tits and an electrical connection at the right side of the fire wall (Just left of the raidiator reservour) Is this connection right?

Yes. that's how it's connected on my car. I believe it's part of the HVAC system, but not sure of the exact function. There should be a white plastic vacuum hose connected to the second tit which goes through the firewall.

Where does the other vacuum hose comming from the first black piece on the brake master cylinder hose go?

That one goes to the EGR control valve (N18) - shown on the diagram above the N75 and below the ECU, the hose labeled vacuum supply

Simon

 

[HueyTDI]

hope i can get help quickly, on the ALH hose diagram 1.9L, there is hose that is connecting to the top of the air cleaner cover. it is leading from the EGR. i do not have a tit there or anywhere on the cover. i cannot locate any tit in the area to where this hose needs to connect. is it possible the hose is to be left as is? i have a 2003 tdi without turbo.

 

[TonyJetta]

If it's like the TDI motors, it's just an atmosphere vent, for closing the EGR valve.

You may want to wrap a rag around it to prevent it from sucking in any contaminants...like a filter.

Tony

 

[P2B]

hope i can get help quickly, on the ALH hose diagram 1.9L, there is hose that is connecting to the top of the air cleaner cover. it is leading from the EGR.

The hose connection from the EGR and N75 solenoids to the airbox on a 2003 Jetta TDI is circled below - is that what you mean?

i have a 2003 tdi without turbo.

What happened to your turbo?

Simon

 

[Danigizzle]

Is this an AGR engine??

 

[P2B]

Diagram is for an AHU

 

[Danigizzle]

Do you know anyone with an AGR diagram??

 

[Haydenkoi]

There are several subtle differences. Motor mounts, vacuum pump, injection pump, and many others that I am not aware of.



Look on the timing belt cover; see the barcode? Also, the ALH intake manifold points to the Passengers side (like this pic); AHU/1Z points to the drivers side.

Can you take the n18 out after deleting all the hoses attached to it since it’s sitting there serving no purpose or if you unplug it will it start screwin with the motor?

 

[garciapiano]

Can you take the n18 out after deleting all the hoses attached to it since it’s sitting there serving no purpose or if you unplug it will it start screwin with the motor?

You can indeed delete it after deleting the EGR.