'84 300td turbo intake leak?
 

I just bought a 300td parts car, my first Mercedes. It was in a wreck on the front passenger side that bent the frame of the car. I bought the car for the engine so I just took it for a steep hill climb which was the first time i have put any load on the engine since the test drive. Climbing the hill, I noticed that other than the usual turbo noise there was an additional loud hiss when the turbo spooled or had any pressure. Are leaks between the turbo and intake common on these cars?

none of the ones I've had leaked...

With the Engine Cold spray down the manifolds and turbo and parts of the Exhaust in the Engine Compartment with a mix of 1 gallon of Water to 1 cup of Dawn Dish Soap. Reduce the formula as you like.

That makes a mix that will make Bubbles.

With the Engine cold and revved up you should see bubbles where the leak is.

The Turbo to Manifold is sealed by 2 O-rings.

It is possible for the Manifold Nuts to be loose. However, be careful tightening them as the end of the Stud going into the Head has only 4 complete threads on it.

If there is a big enough leak it is possible to over speed the Turbocharger.

My biggest worry is that the turbo was "bumped" during the wreck since collision was on the passenger side front fender. Hopefully I am just being paranoid and it's just a blown seal somewhere. Still I definitely do not want to ruin the turbo.

There's also a rubber seal on the U-tube before the turbo which can cause a leak if it's out of place.

The waste gate hose may have an issue.

That would make a lot of sense. If the waste gate was not working properly it would not have correct manifold pressure. The engine performed how I would expect a non turbo 617 to perform. Does the wate gate run off of the vacuum system because I already anticipate that the vacuum pump may have issues or need a thorough cleaning. I have to stop the engine with the fuel cut off.

No vacuum, if an early turbo. Later units had an ARV on the front which has a vac line.

Here's a pic of the hose.