[submarshall]

I'm having an oil burning issue with my 08 135i after a DP install too!! I've been doing a lot of research and this is a little something that i have found that my fix ALL of our problems.

This is all from Garrett turbos website.

Oil Supply & Drainage
Journal Bearing Turbo
Journal-bearings function similarly to rod or crank bearings in an engine:
oil pressure is required to keep components separated. An oil restrictor is
generally not needed except for oil pressure-induced leakage.
The recommended oil feed for journal bearing turbochargers is -4AN or
hose/tubing with an ID of approximately 0.25”.
Be sure to use an oil filter that meets or exceeds the OEM specifications.
Ball Bearing Turbo
An oil restrictor is recommended for optimal performance with ball bearing
turbochargers. Oil pressure of 40 – 45 psi at maximum engine speed is
recommended to prevent damage to the turbocharger’s internals. In order to
achieve this pressure, a restrictor with a 0.040” orifice will normally suffice,
but you should always verify the oil pressure entering the turbo after the restrictor in insure that the components are functioning properly.
Recommended oil feed is -3AN or -4AN line or hose/tubing with a similar ID.
As always, use an oil filter that meets or exceeds the OEM specifications.
OIL LEAKAGE SHOULD NOT OCCUR ON A PROPERLY FUNCTIONING
SYSTEM IF RESTRICTOR IS NOT USED UNLESS THE SYSTEM
PRESSURE IS EXCESSIVELY HIGH.
Oil Drain
In general, the larger the oil drain, the better. However, a -10AN is typically
sufficient for proper oil drainage, but try not to have an inner diameter smaller
than the drain hole in the housing as this will likely cause the oil to back up
in the center housing. Speaking of oil backing up in the center housing, a
gravity feed needs to be just that! The oil outlet should follow the direction of gravity +/-35° when installed in the vehicle on level ground. If a gravity feed is not possible, a scavenge pump should be used to insure that oil flows freely away from the center housing.
Avoid:
• Undulations in the line or extended lengths parallel to the ground
• Draining into oil pan below oil level
• Dead heading into a component behind the oil pan
• Area behind the oil pan (windage tray window) where oil sling
occurs from crankshaft When installing your turbocharger, insure that the turbocharger axis of rotation is parallel to the level ground within +/- 15°. This means that the oil inlet/outlet should be within 15° of being perpendicular to level ground.
Water Lines
Water cooling is a key design feature for improved durability and we recommend that if your turbo has an allowance for water-cooling, hook up the water lines. Water cooling eliminates the destructive occurrence of oil coking by utilizing the Thermal Siphon Effect to reduce the Peak Heat Soak Back Temperature on the turbine side after shut-down.
In order to get the greatest benefit from your water-cooling system, avoid
undulations in the water lines to maximize the Thermal Siphon Effect.

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, drain is below the oil level in the pan
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 windage 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°.

Tell me what you think guys!!

[enrita]

the cats in the oem dps masks a lot existing smoking issues. Without the cats the smoke is more pronounced.
Is it really oil smoke? U sure is not water vapour/condense .
Do not attempt to modify the stock turbos. If you are smoking oil is because they are leaking=toasted.

[submarshall]

I know it its burning oil because it smells bad and a drop of oil came out of my exhaust pipe. I know, that sounds horrible!! I just dont want to put my stock DP's back on and take it to the dealer and them tell me there is nothing wrong with the turbos.