whats the small hole for on the side of the turbo rite by where the air intake hose hooks to the turbo and why is mine leaking oil out of this hole should the air intake hose be slid farther forward to cover this hole

 

A hole that's actually on your turbo or on your rubber going to the filter? It's been more than a minute since I've changed a turbo on mine but I don't remember there being any holes in the housing other than for the oil circulation and the you loosen off to "adjust" the position of the output on install(not sure if they go into the oil) If any of these bolts or the ears that attach to them are missing they absolutely need replacing

 

Excessive blow by going into your intake would be why it's leaking oil if it's not near where the oil is circulated through the turbo but I don't know of a hole that should be in the location I think you're describing?

 

Excessive blow by

Before you even entertain the thought, check that the air filter isnt clogged up.
A dirty neglected air filter is the biggest CONTRIBUTOR of crankcase oil vapor accumulation in the intake air tract, which is almost always present on most 6.5s...

Clean unrestricted air filter.. Then check to ensure the CDR Valve is functioning properly AND that all the rubber gromet(s) (including where CDR slips into rocker cover), flex hoses, intake air flex boot, everything used to SEAL the "crankcase ventilation system." Not very effective if its leaking a lil here, lil there, anywhere.

Its perfectly NORMAL to find some oil accumulation inside the flex boot, turbo compressor housing, turbo compressor wheel as well as upper and lower intake manifolds..
If excessive, may indicate blow by or its been neglected badly. Poor maint, a dirty air filter causes excessive vacuum, spooling turbo (building mo' boost) only exacerates the problem..


Red Circle is CDR Valve, green arrow is another spot where it likes to start leaking or seeping oil. Always silicone the Turbo coupling on both ends to prevent oil leakage/seepage and boost leaks.







See attachments for figures/illustrations.

Crankcase Ventilation System

General Description
The crankcase ventilation system used on [GM's 6.5TD] diesel engines is designed to maintain a slightly negative (vacuum) crankcase pressure across the [entire] speed range. The system consist of a Crankcase Depression Regulator (CDR) valve, located on the right valve cover and the attaching vent hose/pipes to the engine [air] inlet system. The CDR valve is only used to regulate crankcase pressure between 0" and -4" water depression over the engine speed range. The CDR valve is NOT an oil separator or a crankcase effluent flow regulator. Hence, the CDR valve DOES NOT prevent oil droplets/mist [vapors] from entering the intake system, nor does it effect engine oil consumption.
The Intake manifold vacuum [pre-turbo] acts against a spring loaded diaphragm to control the flow of crankcase gases (Figures 11-1 and 11-2). Higher intake vacuum (or highintake restriction, e.g. plugged air filter) levels pull the diaphragm closer to the top of the outlet tube. This reduces the vacuum level from getting to high in the crankcase. As the intake vacuum decreases, the spring pushes the diaphragm away from the top of the outlet tube to prevent crankcase pressure from going positive.

CDR Valve Test
The purpose of the CDR valve is to maintain 0" to -4" inches of water vacuum in the crankcase at all engine speeds, assuming that piston/ring combustion blow by is not excessive (less than 4cfm). Too little vacuum will tend to force oil leaks.
The CDR valve is checked with a water manometer. The U-tube manometer (Figure 11-3) indicates pressure or vacuum by the difference in height of the two columns of fluid.
If crankcase vacuum is too high (greater than -4" water), dirt or dust can more likely be pulled into the crankcase cavity(pulled through front/rear crankcase seal, etc...) and contaminate the oil. If crankcase pressure is positive, engine oil leaks are more likely to occur around engine seals and gaskets.

1... Connect one end of the manometer to the engine oil dipstick hole. The other end of the manometer is vented to atmosphere.

2... NON TURBO- Disconnect CDR hose from CDR valve in rocker cover so valve can vent freely to atmosphere.
TURBO- Unplug rubber vent tube from turbo inlet elbow.

NOTICE: Do Not allow any foriegn material to enter inlet system where CDR valve vent hose has been disconnected.

3... Run engine through no load speed range (gear selector in park) and observe manometer readings. If manometer reading is +4" water or less positive pressure, reconnect CDR system and proceed to Step 4. If manometer is higher than +4" water positive pressure, refer to Section 6A ["Engine, Driveability and Diagnosis"].

4... Install air cleaner.

5... Start engine and observe manometer reading. It should read zero to one inch (0-1") of water (vacuum) at idle to approximately 3-4 inches of water (vacuum) at 2000 RPM.
Add the amount that the manometer column travels up, to the amount that the column travels down to obtain total water pressure (vacuum). An example of a manometer reading is as follows: One-half inch above zero plus one-half inch below zero equals one inch vacuum reading (1/2" + 1/2" = 1") (Figure 11-3).

On-Vehicle Service
CDR Valve And Hoses
Figures 11-4 and 11-5

NOTICE: Do Not allow any solvent(s) to come in contact with the diaphragm of the crankcase depression regulator valve, because the diaphragm will fail.

The crankcase depression regulator valve is replaced as an assembly. Replace hoses as required, if inspection indicates cracks or decay.
Refer to Section 0B in appropriate service manual for diesel crankcase ventilation system maintenance requirements.

Section OB- Maintenance and Lubrication- To paraphrase..
As an emissions control device, both Maintenance Scheldule I and II call for a "CDRV System Inspection" annually and/or at 60,000 mile intervals.












Good Luck..

 

thanks