Service Manual

ISB, ISBe and QSB (Common Rail [...] Crankcase Blowby, Measure
Section 14 - Engine Testing - Group 14 Page 14-41
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Preferred Turbocharger Isolation Method:
Install a hose assembly with two shutoff valves (A and B),
as shown in the illustration, between the turbocharger and
turbocharger drain line location in the cylinder block. The
valves must have a minimum inside diameter of 19 mm
[0.75 in]. Place the other hose in a 8 to 9 liter [2 to 3 gal]
container.
NOTE: Some turbocharger oil drain tubes are a single
one piece tube. It can be necessary to create a
turbocharger isolation tool. Use a new or used
turbocharger drain line and cut a middle section out of the
turbocharger drain line to fit the check valves and hoses.
Close the valve (A) that allows oil to drain into the bucket.
Open the valve (B) that allows oil to drain into the engine.
Operate the engine at rated speed and under load by
either:
• For engine testing, a chassis dynamometer or engine
dynamometer
• A stall speed test (for engines equipped with automatic
transmissions only).
Operate the engine at rated rpm and full load until a
steady reading is obtained.
NOTE: When measuring blowby, the value can “spike”
initially as the engine reaches peak power and rated
speed. Wait for the blowby measurement to stabilize
before taking a reading.