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US 9,068,486 B2Granted
Crankcase integrity breach detection
AssigneeFord Global Technologies, LLC
InventorsJohn Eric Rollinger, Robert Roy Jentz, Ross Dykstra Pursifull
Life of this patent
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Abstract
Methods and systems are provided for using a crankcase vent tube pressure or flow sensor for diagnosing a location and nature of crankcase system integrity breach. The same sensor can also be used for diagnosing air filter plugging and PCV valve degradation. Use of an existing sensor to diagnose multiple engine components provides cost reduction and sensor compaction benefits.
Claims20
An engine crankcase ventilation system, comprising:
- an engine including an intake passage and a crankcase;
- a crankcase vent tube mechanically connected to the intake passage upstream of a compressor, the tube also mechanically connected to the crankcase via an oil separator, the vent tube located external to the engine;
- a sensor coupled in the crankcase vent tube for estimating a vent tube pressure;
- and
- a control system with computer readable instructions for,
- during an engine start,
- indicating crankcase ventilation system degradation based on each of a transient dip in the vent tube pressure being lower than a threshold amplitude during engine cranking when manifold airflow is below a threshold and a change in vent tube vacuum being lower than a change in manifold airflow during engine running when manifold air flow is above the threshold.
4 more elements
A method for an engine, comprising:
- indicating crankcase ventilation system degradation based on characteristics of a transient dip in crankcase vent tube pressure, during engine cranking.
A method for an engine, comprising:
- indicating disconnection of a crankcase vent tube from an engine crankcase ventilation system based on a transient change in airflow through the crankcase vent tube during engine cranking.
Dependencies are inferred from the claim text.