First something which I think is rather scary: I was cleaning my intake manifold, and I found something disturbing in the base part of the manifold. It was a small piece of metal, a millimeter or so thick, a quarter inch wide and maybe 2 inches long. How could that possibly get past the airfilter?

Next: is the bronze round thing on top of the intake the EGR valve? What does it do? Its just one part, and a wire leading to it.

Next: http://myweb.cableone.net/tbogemirep/

The person who wrote this page mentions removing what he calls the 'turbo muffler tube' (I think the horizontal gray plastic tube attached to hose leading to the turbo). Can I remove it too, just like that, and just pop a freeze plug in its place? (I love whistling turbo's :) )

Hopefully thats not a piece of your compressor wheel in the intake, better pull the boot off the turbo and have a look to be sure.

The Boss on top of the EGR is the Vacuum pot that operates the valve underneath, and the hose connected to it goes to a switch that controls how much vacuum is applied and thus how open the valve moves.

The commonly called 'turbo muffler' can very safely be removed, there's another name for it, but a freeze plug will work in its place.

Thanks for the answers, and I will take a look at the turbo compressor wheel, it doesn't make a strange sound though...

A picture would be helpful to try and identifying the metal strip. It sounds like it might be the gasket that is suposed to be between the EGR and the intake manifold. If a piece that large had come off the compressor the imbalance would have caused an almost immediate self destruction.

Next: is the bronze round thing on top of the intake the EGR valve? What does it do? Its just one part, and a wire leading to it.

Next: http://myweb.cableone.net/tbogemirep/

The person who wrote this page mentions removing what he calls the 'turbo muffler tube' (I think the horizontal gray plastic tube attached to hose leading to the turbo). Can I remove it too, just like that, and just pop a freeze plug in its place? (I love whistling turbo's :) )That person be me, I see from your signature you are in NL, how smart are your emissions inspectors over there, the stuff you are talking about bypassing is emission related equipment & could get you in some trouble, I know from my many visits to the EU your officials can be somewhat anal about modifing vehicles for performance.

If you want PM me and I can give you some ideas on how to improve performance and still be safe. Turbo muffler is removable I used a freeze pluig in mine, a photo of the metal chunk you found would be handy.

Bronze thing in middle is EGR valve on S "L56 engine" that should be a nylon tube and not a wire leading to it's actuation diaphragm.

Turbine Doc:

Funny you should mention EU regulations and laws, some time ago some smartass tried to ban pickups and SUV in one of our big city's:mad: Didn't work though):h
As for emissions, it isn't neccesary to have a cat on a diesel coupled to an automatic transmition (strange I know). I've never seen anybody been checked for emissions.

On the freeze plug: what make/type/brand is it? Do you need silicon or something to make it airtight?

As for the EGR: it could alse be a nylon tube, yes, it just fits on a little extension on the vacuum pot (and leads to the solenoids, right?).

Somebody threw the metal debris away:( so no pics, sorry. MDT makes the point that a piece that large of the compressor wheel would result in instant destruction of the turbo, and I guess that true. So that's ruled out.

As for the gasket between EGR and intake manifold: there is some sort of isolation strip in the bottom of the mount of the vacuum pot, but that is still complete. I also heard of a gasket between the elbow-part of the intake and the manifold itself, but when I first took of the elbow-part, it wasn't there at all. And the piece of debris wasn't shaped right to be that gasket (I remember it was basicly a flat ring, while the debris was square).

I guess I can call it an UFO: Unidentified Foreign Object):h

Thanks for the replies,

Cheers, Helmet

Just sent you a PM

Um is there supposed to be a gasket between the elbow-part and the manifold?

There isn't one on my truck, so MAYBE the chunk in the manifold is/was part of the gasket...

There are a lot of stains in the intake, so I guess thats it...

I lost a piece of a compressor wheel into the intake. The compressor would scream above 1200 rpm like a banshee. I never did find that chunk even when i pulled the head off the turbo side.

Nah the turbo is quiet, you can barely hear it whistle, I'm sure its not
a problem with the compressor wheel...

There's a gasket between the upper and the lower part of the intake. I happen to have a new gasket at hand, I'll make a picture of it.

The gasket is not made of metal but of something looking similar to asbestos.

BTW, are you sure that you have the turbo muffler TDoc has removed and plugged? I didn't have one on mine.

Hi lee, well you have my email, so you know where to send the pic :)

Also, is this just the 'ring' in the inside, or the bigger gasket running along the
edge between the upper and lower part of the intake? I have neither.

I do have the gasket between the vacuum pot and the upper part of the intake,
I guess this is the same material as your gasket?

And I'm sure that I have the muffler installed, its a grey plastic tube, about 30 cm long,
running horizontal and extending from the hose between the turbo and the intake.

And do you hear your turbo whistling? Or is it still quiet?

Sorry, I couldn't find that gasket yet ... I'll have to search through some boxes where I keep these things ...

The gasket I have is the large one that goes between the outer ring of the upper and lower intake. I expected to get the smaller gasket for the EGR valve too within the kit, but for some reason it wasn't there. I still have to file a complaint about that ...

If you have the gasket that sits at the bottom of the EGR assembly, on top of the upper part of the intake, I'd say it's the same material as the intake gasket.

Hm, is there a certain year GM started to install the turbo mufflers? I can hear something of my turbo, but it's rather quiet. I'm still going with the stock exhaust and the cat. I can hear a bit more of it with the thermal sound insulation that sits on the underside of the hood removed, though.