Hi guys,

when changing this hose (pointed on pic) on my turbo
I found some oil in it... is it normal and in basics what is that line for anyway ?

TX

cheers,

ChO


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Attached Thumbnails

 

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

The line is there so that Intake Manifold Pressure goes to the Wastegate. If the Intake Manifold Pressure gets higher than the Wastegate Spring setting the Wastegate opens up and diverts the Exhaust Gas away from the Turbocharger slowing the Turbo down and that reduces the Intake Manifold Pressure.

Some of the Oil in the Hose could be from the Blow-by Oil Vapor. It is also possible for Oil leaking into the Compressor side of the Turbocharger to be flung up there and into the Hose; but, if that was happening when you remove the Turbo the Compressor Side of the Tubo would have had a small pool of Oil in it.

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84 300D, 82 Volvo 244Gl Diesel

thanks nine eleven

I did't remove the turbo (pic was taken from net...) just replaced that hose
as it was cracked and ....old


btw is this amount of blow by a sign that engine does not operate as it should
...mine was rebuilt 3000 miles ago...?


cheers,

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

I don't know what to say on how much is normal Blow-by on rebuilt Engine; so I can only speak in general

It also depends on what you mean by Rebuilt Engine.
As far as Blow-by goes ideal would be new Pistons, Rings and Liners with the Head also rebuilt so no exhaust gas or Manifold Pressure can get by the Valve Stems.
Next best would be new Liners with old Pistons that are within spec and new Rings and the Head rebuilt.

If you used the used Cylinders and Pistons and just replaced the Rings I would expect Blow-by because the used Cylinders are likely not round but the New Piston Rings are.

With used Pistons there is a ring groove width issue. If they are worn more Blow-by can get past then if they were not.

If you Engine was completely rebuilt at 3000 miles it may not even be broke in yet and there can be Blow-by from that.

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84 300D, 82 Volvo 244Gl Diesel

it was option 2

new Liners with old Pistons that are within spec and new Rings and the Head rebuilt ....

thanks mate,

will wait,will see

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

It could be the Rings have not seated well. You could load your Car up with your heaviest Friends and stuff in the Trunk and go for a fast ride where you can pull up some Hills.

I have never had a Mercedes Apart so I don't know what to expect to find when the Ring Grooves are examined. I know when I rebuilt my Volvo Diesel all of the upper Compression Ring Grooves were worn to the extent there was actually a step in the Metal; clealy no good.

If the Ring Grooves on the Piston were within spec but close to the worn limit that could contribute to Blow-by.

You never mentioned if the Air Inlet before it goes into the Turbocharger was also covered with Oil or if there is Oil inside of the Air Filter Housing?

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84 300D, 82 Volvo 244Gl Diesel

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in due hood limitations of the SEC I had to change my air setup
to SprintFilter (metal housing) so it is bit different than stock,...but
on the inlet of the turbo I can find,.. say, drop or two of oil....


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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

Hello,

trying to figure out what this hose does.

I installed a boost guage and was experimenting with a couple of these hoses. My setup is like the one in the picture at the top of this post. I had disconnected the hose off the nipple on the waste gate spring tension adjustment cap and set it aside while i went for a drive. I noticed that my boost was up about 2 psi more than usual, it would max around 12psi. When i popped the hood after the drive i noticed a little bit of oil/soot/something had come out the end of the disconnected hose.

what exactly does this hose do? why would it be generating pressure towards the part of the turbo that has the wastegate tension adjustment stuff? where exactly is the "wastegate" located, is it at one of the ends of this hose? I thought it was at the turbine near the exhaust down pipe?

In layman's terms, the wastegate hose and wastegate are between the engine intake side and the exhaust. It mechanically limits the amount of pressure for the intake. If this preset pressure is exceeded then the wastegate opens to vent it to the exhaust.

Here is a portion of the FSM that explains it with diagrams: http://www.startekinfo.com/StarTek/outside/12253/program/Engine/617/09-450.pdf

You also have a "backup" overboost protection valve that is designed to limit fuel to the injection pump, via the alda.

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Sam

84 300SD 350K+ miles ( Blue Belle )

That is not correct. Pressure from the intake manifold is not vented into the exhaust system. Excess manifold pressure opens the bypass valve, which bypasses exhaust gases around the turbine, thereby limiting turbine speed and manifold pressure.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Correct, my fingers and brain had a disconnect. The wastegate limits the pressure to the exhaust turbine. Which, in turn, relieves the pressure of the intake.

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Sam

84 300SD 350K+ miles ( Blue Belle )