Not sure what this is - air intake pipe?

[Bushman Steve]

Hey Guys,

New to the forum and looking for some guidance on a new issue with my 1.6l diesel caravelle....1988.

I've had a look at the mechanical diagrams in the manuals online and can't seem to find a clear answer.

Started having a deeper tone from engine as if exhaust had gone or airbox had fallen off. Took a look and noticed the opening in the image.

I cant seem to find a pipe or another opening that this could have connected to so a little lost as to what this is, what it's for and how to sort...My first thought is that there should he a cap over it but I don't know and if correct don't even know what I'm searching for.

I've done what I can to figure this out and now calling on you folks for some help. Images below

https://drive.google.com/drive/folders/ ... kP4vdvp4bT

Thanks
Steve

[R0B]

For future reference.

[Rascal]

You have lost your blow off valve and obviously the clamp that holds it on.. Its purpose is to release any excess boost pressure the turbo creates to prevent engine damage. So now any boost the turbo creates is vented to the atmosphere so I imagine the performance will be dramatically decreased.

[ZsZ]

It should look like this:

[Bushman Steve]

Thanks gents. Makes perfect sense. Appreciate the help. Doesn't seem to be a well stocked part, do you think any after market valve will do the job that fits or should I look for as per above image?

[ZsZ]

IMO it is not really necessary VW did not use it on other later TD engines.
You can plug it with a plug turned on a lathe. Here is a drawing I made:
https://www.dropbox.com/s/8liy3shz0qysx ... G.pdf?dl=1
However you will need the OE V-band clamp.

[davidoft1]

IMO it is not really necessary VW did not use it on other later TD engines.
You can plug it with a plug turned on a lathe. Here is a drawing I made:
https://www.dropbox.com/s/8liy3shz0qysx ... G.pdf?dl=1
However you will need the OE V-band clamp.

They have electronic boost control now

[ZsZ]

IMO it is not really necessary VW did not use it on other later TD engines.
You can plug it with a plug turned on a lathe. Here is a drawing I made:
https://www.dropbox.com/s/8liy3shz0qysx ... G.pdf?dl=1
However you will need the OE V-band clamp.

They have electronic boost control now

The AAZ's had no BOV, neither electronic boost control.
I am not sure why VW used the BOV on some 1.6TD engines but they ditched on the 1.9s