Protege L4-1839cc 1.8L DOHC (1990)
Engine Mount: Customer Interest
Engine - Vibration at Idle
Bulletin No.: 003/93
Issued: 4/14/93
Revised:
Category
B
Applicable Model/s
1993 MX-6/626
(A/T Models)
Subject:
4-CYLINDER ENGINE VIBRATION
DESCRIPTION
Due to inherent characteristics of 4-cylinder engines, vehicles equipped with automatic transmissions will transmit vibrations and resonance into the
vehicle's interior during idle. This is a normal characteristic resulting from transversely-mounted powertrain designs. However, some vehicles may
exhibit a higher than normal amount of idle vibration and resonance.
Before performing the repair procedures listed in this bulletin, perform the following "Quick Checks" to determine if the level of vibration can be
reduced effectively.
1.
Compare the affected vehicle's vibration and resonance to one or more equally-equipped vehicle(s) from the dealer inventory. Perform this in
"Drive" and "Reverse" with the air conditioner on.
2.
Perform a visual inspection of Engine Mount No. 3 to verify it is centered in the bracket. Refer to Step 2 in the repair procedures of this bulletin
for details.
3.
Check base idle speed at normal operating temperature and if necessary, set to 700-750 rpm per Section B of the applicable Workshop Manual.
If the results indicate the level of vibration to be equal to other equally-equipped vehicle(s) and/or the Engine Mount No. 3 is centered in the bracket,
performing the repair procedures in this bulletin will not reduce idle vibration. Do not attempt further repairs and advise the vehicle owner of the
characteristics of transversely-mounted 4-cylinder powertrains.
If the affected vehicle's level of vibration is comparably greater than the other vehicles or if Engine Mount No. 3 is not centered, perform the following
repair procedures to reduce and isolate the idle vibration.
REPAIR PROCEDURE
Located in this bulletin.
