Buick Regal: Symptoms - Engine Mechanical
Strategy Based Diagnostics
1. Perform the Diagnostic System Check - Vehicle before using the symptom
tables, if applicable.
2. Review the system operations in order to familiarize yourself with the system
functions. Refer to
Disassembled Views, Engine Component Description, and Lubrication Description.
All diagnosis on a vehicle should follow a logical process. Strategy based
diagnostics is a uniform approach for
repairing all systems. The diagnostic flow may always be used in order to
resolve a system condition. The diagnostic
flow is the place to start when repairs are necessary.
Visual/Physical Inspection
- Inspect for aftermarket devices which could affect the operation of the
engine.
- Inspect the easily accessible or visible system components for obvious
damage or conditions which could
cause the symptom.
- Check for the correct oil level, proper oil viscosity, and correct
filter application.
- Verify the exact operating conditions under which the concern exists.
Note factors such as engine RPM,
ambient temperature, engine temperature, amount of engine warm-up time, and
other specifics.
- Compare the engine sounds, if applicable, to a known good engine and
make sure you are not trying to correct
a normal condition.
Intermittent
Test the vehicle under the same conditions that the customer reported in
order to verify the system is operating
properly.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to
diagnose the symptom:
- Base Engine Misfire without Internal Engine Noises
- Base Engine Misfire with Abnormal Internal Lower Engine Noises
- Base Engine Misfire with Abnormal Valve Train Noise
- Base Engine Misfire with Coolant Consumption
- Base Engine Misfire with Excessive Oil Consumption
- Engine Noise on Start-Up, but Only Lasting a Few Seconds
- Upper Engine Noise, Regardless of Engine Speed
- Lower Engine Noise, Regardless of Engine Speed
- Engine Noise Under Load
- Engine Will Not Crank - Crankshaft Will Not Rotate
- Engine Compression Test
- Turbocharger Leaking Fluids Externally
- Turbocharger Noise
- Turbocharger Smoke or Smell
- Turbocharger Loss of Boost Pressure
- Oil Consumption Diagnosis
- Oil Pressure Diagnosis and Testing
- Oil Leak Diagnosis
- Drive Belt Chirping, Squeal, and Whine Diagnosis
- Drive Belt Rumbling and Vibration Diagnosis
- Drive Belt Falls Off and Excessive Wear Diagnosis
- Drive Belt Tensioner Diagnosis
BASE ENGINE MISFIRE WITHOUT INTERNAL ENGINE NOISES
BASE ENGINE MISFIRE WITH ABNORMAL INTERNAL LOWER ENGINE NOISES
BASE ENGINE MISFIRE WITH ABNORMAL VALVE TRAIN NOISE
BASE ENGINE MISFIRE WITH COOLANT CONSUMPTION
BASE ENGINE MISFIRE WITH EXCESSIVE OIL CONSUMPTION
ENGINE NOISE ON START-UP, BUT ONLY LASTING A FEW SECONDS
UPPER ENGINE NOISE, REGARDLESS OF ENGINE SPEED
LOWER ENGINE NOISE, REGARDLESS OF ENGINE SPEED
ENGINE NOISE UNDER LOAD
ENGINE WILL NOT CRANK - CRANKSHAFT WILL NOT ROTATE
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DEFINITION: Excessive white smoke and/or coolant type odor coming from
the exhaust pipe may indicate
coolant in the combustion chamber. Low coolant levels, an inoperative cooling
fan, or a faulty th
Special Tools
EN 35667-A Cylinder Head Leakdown Tester
For equivalent regional tools, refer to Special Tools.
NOTE: A leakage test may be performed in order to measure
cylinder/combustion chamber
lea
Diagnostic Aids
A chirping or squeal noise may be intermittent due to moisture on the
drive belts or the pulleys. It may be
necessary to spray a small amount of water on the drive belts in order
SEE MORE:
Diagnostic Instructions
Perform the Diagnostic System Check prior to using this diagnostic
procedure: Refer to Diagnostic System
Check - Vehicle
Review the description of Strategy Based Diagnosis: Refer to Strategy
Based Diagnosis
An overview of each diagnostic category can be found here: R
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptor
DT