Crankcase Ventilation System Inspection/Diagnosis

WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Symptom	Correction
External oil leak	Inspect for any of the following conditions: Restricted or kinked positive crankcase ventilation (PCV) hose or engine vent hose Damaged, incorrect, or incorrectly installed PCV hose Excessive crankcase pressure
Rough Idle	Inspect for any of the following conditions: Restricted or kinked PCV hose or engine vent hose Leaking (damaged) PCV hose Vacuum hoses worn or not properly installed
Stalling or slow idle speed	Inspect for any of the following conditions: Restricted or kinked engine vent hose Leaking (damaged) PCV hose
High idle speed	Inspect for a leaking (damaged) PCV hose
Sludge in the engine	Inspect for restricted or kinked PCV hose or engine vent hose