Engine Driven Accessories Related To Engine Order; Engine Order Related Disturbances - Suzuki XL7 2007 Service Manual

1D-56 Engine Mechanical:

Engine Driven Accessories Related to Engine Order

Engine driven accessory systems can be related to specific engine orders depending upon the relationship of the
accessory pulley diameter to the crankshaft pulley diameter. For example:
• If the crankshaft pulley measured 20 cm (8 in) in diameter and one of the engine driven accessory pulleys
measured 10 cm (4 in) in diameter, then that accessory pulley would rotate 2 times for every one rotation of the
crankshaft pulley. If that accessory system was not isolated properly, or was not operating properly, it would be
identifiable as a 2nd order engine related disturbance.
• In like manner, if an engine driven accessory pulley measured 5 cm (2 in) in diameter, then that accessory pulley
would rotate 4 times for every one rotation of the crankshaft pulley. If that accessory system was not isolated
properly, or was not operating properly, it would be identifiable as a 4th order engine related disturbance.
Engine driven accessories that contribute to, are excited by, or are the sole cause of a disturbance are usually doing
so because of improper isolation that causes a transfer path into the passenger compartment or to another major
component of the vehicle body.
Using the J 38792-VS, Vibrate Software, accurately measuring the diameters of the accessory pulleys and the
crankshaft pulley, and performing the appropriate diagnostic procedures completely will lead to the specific accessory
system which is either contributing to, or causing the customer's concern.

Engine Order Related Disturbances

L4
Engine W/O Balance
Order Shaft
Abnormal -
½ Order
Likely Single
Torque
Cylinder
Sensitive
Misfire
Abnormal -
Likely
1st Order
Component
Imbalance
Possible
1½ Order
Engine Driven
Torque
Accessory
Sensitive
Related
Characteristic
of Engine
2nd Order
Arrangement
Non
- Possible
Torque
Powertrain
Sensitive
Isolation
Related
Characteristic
- ENGINE
FIRING
FREQUENCY
- Possible
2nd Order
Powertrain
Torque
Isolation
Sensitive
Related
Possible
Engine Driven
Accessory
Related
L4
With Balance L5
Shaft
Abnormal - Abnormal -
Likely Single Likely Single
Cylinder Cylinder
Misfire Misfire
Abnormal - Abnormal -
Likely Likely
Component Component
Imbalance Imbalance
Possible Possible
Engine Driven Engine Driven
Accessory Accessory
Related Related
Possible Possible
Engine Driven Engine Driven
Accessory Accessory
Related Related
Characteristic
- ENGINE
FIRING
FREQUENCY
- Possible Possible
Powertrain Engine Driven
Isolation Accessory
Related Related
Possible
Engine Driven
Accessory
Related
Engine Arrangement
L6 60 Degree V6
Abnormal -
Abnormal - Likely Single
Likely Single Cylinder
Cylinder Misfire and/or
Misfire EGR/Fuel
Variance
Abnormal - Abnormal -
Likely Likely
Component Component
Imbalance Imbalance
Abnormal -
Likely Bank to
Possible Bank EGR/
Engine Driven Fuel Variance
Accessory Possible
Related Engine Driven
Accessory
Related
Characteristic
of Engine
Possible
Arrangement
Engine Driven
- Possible
Accessory
Powertrain
Related
Isolation
Related
Possible Possible
Engine Driven Engine Driven
Accessory Accessory
Related Related
90 Degree V6
With Balance 90 Degree V8
Shaft
Abnormal -
Likely Single Abnormal -
Cylinder Likely Single
Misfire and/or Cylinder
EGR/Fuel Misfire
Variance
Abnormal - Abnormal -
Likely Likely
Component Component
Imbalance Imbalance
Abnormal -
Likely Bank to
Bank EGR/ Possible
Fuel Variance Engine Driven
Possible Accessory
Engine Driven Related
Accessory
Related
Characteristic
of Engine
Possible
Arrangement
Engine Driven
- Possible
Accessory
Powertrain
Related
Isolation
Related
Abnormal -
Likely Bank to
Possible Bank EGR/
Engine Driven Fuel Variance
Accessory
Related
Possible
Engine Driven
Accessory
Related