Buick Regal: Crankcase Ventilation System Description
General Description
A crankcase ventilation system is used to consume crankcase vapors in the combustion process instead of venting them to atmosphere. Fresh air from the intake system is supplied to the crankcase, mixed with blow by gases and then passed through a calibrated orifice into the intake manifold.
Operation
.png)
The primary control is through the positive crankcase ventilation (PCV) valve (2) which meters the flow at a rate depending on intake manifold vacuum. The PCV valve is an integral part of the camshaft cover. Fresh air is introduced to the engine through PVC (1) under normal operating conditions. If abnormal operating conditions occur, the system is designed to allow excessive amounts of blow by gases to back flow through the crankcase vent valve (3) into the intake system to be consumed by normal combustion.
Only on turbocharged engines, there is a one way valve (2) in the camshaft cover in order to prevent the crankcase from being pressurized by positive pressure in the intake manifold when the turbocharger is in operation. When the turbocharger is operational, the pressure in the intake manifold can exceed atmospheric pressure which, without the one way valve, would force oil and PCV gases out of the camshaft cover and into the induction system, via the hose to the camshaft cover. This can cause coking of the throttle body and induction system, and can reduce the efficiency of both combustion and the intercooler system, in normal operation the PCV gases are drawn into the air stream post intercooler (6). However, when the turbo is spooled up the turbo can become the vacuum source for the vent system.
PVC#4 controls the max. flow so the crankcase stays at a normal vacuum during normal operating conditions.
Results of Incorrect Operation
A plugged orifice may cause the following conditions:
- Rough idle
- Stalling or slow idle speed
- Oil leaks
- Sludge in engine
A leaking orifice may cause the following conditions:
- Rough idle
- Stalling
- High idle speed
READ NEXT:
Engine Component Description
Engine Description
Cylinder Block
The cylinder block is constructed of aluminum alloy by precision
sand-casting. The block has 5 crankshaft bearings
with the thrust bearing located on the second bear
Use of Room Temperature Vulcanizing (RTV) and Anaerobic Sealant
Cleaning Mating Part Surfaces for RTV Joints
RTV sealant depends greatly on adhesion to the mating parts in order to form
and maintain a robust sealed joint. As
with any adhesion system, proper surfa
Special Tools and Equipment
SPECIAL TOOLS
DT-45866
J-45866
Input Shaft Seal Installer
EN-8062
J-8062
KM-348
Valve Spring Compressor - Head Off
EN-8087
J-8087
Cylinder Bore Gauge
EN-21867-850
J-21867-850
KM-498-B
KM-6106
83 93
SEE MORE:
Power Transfer Unit Case Assemble
Power Transfer Unit Idler Gear Shaft Tube and O-ring, Input Shaft Bearing
Race and Shim, and Idler Gear Shaft Bearing
Race and Shim Installation
Power Transfer Unit Idler Gear Shaft Access Tube O-ring- Rear
Power Transfer Unit Idler Shaft Tube
Procedure
The tube orientation for assembly. In
Wire to Wire Repair - Steering
Special Tools
EL-38125-10 Splice Sleeve Crimping Tool (non GMNA)
J-38125-5A Ultra Torch Special Tool
J-38125-8 Splice Sleeve Crimping Tool (GMNA)
For equivalent regional tools, refer to Special Tools.
WARNING: In order to reduce the risk of personal injury, loss of high
voltage isolation
to gr
