ALH Turbo oil Drain

[narendra.vw]

ALH Turbo(VNT 15) Oil drain clocking.

Till recently, My ALH was running on ‘TD’ exhaust manifold with a ‘modified flanged VNT 15 Turbo’ bolted to it. Left mounting bracket was off ‘TD‘.
Due to technical issues with the modified flange, I had to replace TD with ALH exhaust manifold & redo the left mounting bracket.
Link Thread,
https://www.thesamba.com/vw/forum/viewtopic.php?p=8334151

As a Default the TD manifold with ‘VNT 15 Turbo‘, the oil drain was almost vertical(keeping ground as reference). With this setup I had no issue with the oil seepage into the Intercooler. Drain to Crankcase(oil pan) was off ‘TD’ setup.

With the VNT 15 manifold, running few K miles oil started sneaking into the Intercooler. First I thought it’s the seal rings & replaced the whole cartridge unit. Problem remained the same.
I rechecked the Valve door breather, removed the dipstick to find any back Compression while engine was running. Everything seams to be fine. I was wondering why the same Turbo which was working fine with ‘TD’ setup now has a problem. My mind was running out of Ideas.
After some homework, I found out Garret had a solution.
Garret specifically says that the Drain tilt angle should not be more than 15 degree.Mine was nearer to 40 degree(engine is mounted at 50* tilt).
“Kitchen sink slightly tilted, some water will not reach the drain".
So, my only hope was to reduce the drain angle.

For some lucky ‘TDI’ owners the old setup has worked.


Clocking(CWD) the drain,

This work must be done by a Professional. The input given to him, tilt reduction angle min 25*.
This achieves almost the specified angle for the drain.
There are three threaded holes inside the Turbo case which holds the vane unit. New holes were drilled & threaded at a distance of 22mm from each existing hole. These new holes give me a 25 degree angle reduction.
Work doesn’t stop here. Actuator needs realigning, Oil feed line bit of bending, rerouting & lastly Drain pipe needs to be extended. All the three should be a straight forward work.
Change in position of actuator increases ground Clarence hence, gets self protection.

Detailed Drawing,

New holes.

Rerouting ‘Turbo to IC’. Plastic pipe was replaced by using 38 mm aluminum connector & silicon hose(B).

For time being, banjo bolt being used.

Bolt used in some car’s Brake caliper flexible hose connection.

New drain angle(F/R view).

A small detail I like share. The drain pipe connecting to the crankcase(oil pan) goes all the way to the oil pickup point inside the crankcase. Oil sucking in the Pickup makes the Turbo oil drain faster.

Copy & paste from Garret web

Common Causes of Oil Leakage
A properly installed turbo should NOT leak oil. There are, however, instances where oil leaks occur. The most common causes, depending on the location of the leak, are:

Leakage from compressor and turbine seals
Excessively high oil pressure
Inadequate drain, drain is too small, does not go continuously downhill,
or the location of the drain inside the oil pan is located in a section that has
oil slung from the crank causing oil to back up in drain tube. Always
place oil drain into oil pan in a location that oil from crank is blocked by wind age tray.
Improper venting of crankcase pressure.
Excessive crankcase pressure.
Oil drain rotated past the recommended 35°.

Leakage from compressor seal
Excessive pressure across the compressor housing inlet caused by:
Air filter is too small.
Charge air tubing too small or has too many bends between the air filter
and compressor housing.
Clogged air filter.

Leakage from Turbine seal
Collapsed turbine piston ring from excessive EGT's.
Turbo tilted back on its axis past recommended 15°________________________1


Did few miles on this new setup. No smoke in cold start, everything seems to be fine.
After few more miles, I can give a real feedback.

[thomas73]

Thanks, Narendra.

This is very informative.

How is the engine performing since you last posted?

[narendra.vw]

My finial say after running with this setup & going back to old original setup with a New Turbo.

Present details,
Engine. ALH 1.9 TDI with 50 degree inclined. Oil drain pipe is at the bottom of the oil pan. very simler to 1.6 TD oil pan. Oil used, Mobil ! 0--40 viscosity & fully synthetic.

Turbo is working fine with no oil leakage.

My finial thoughts on this is, 'if Turbo has lost it's life' nothing can be done to stop oil leakage from exhaust. Any Mod is waste of time.

Present Video follows,

Link