Skylark L4-138 2.3L DOHC VIN D MFI QUAD 4 (1989)
Coolant Reservoir: All Technical Service Bulletins
Low Coolant Indicator - On During Hard, Left Hand Turns
Bulletin:
90-8-10
Date:
April, '90
Ref. No.: 90-107-8
Corp. Ref. No.: 076201
SUBJECT:
INTERMITTENT LOW COOLANT INDICATOR LIGHT DURING TURNS- (INSPECT LEVEL/TANK/SWITCH)
MODELS AFFECTED: 1989-90 SKYLARK WITH 2.3L ENGINE (VIN CODE D)
CONDITION:
The low coolant indicator light may illuminate during hard, left hand turns, or during acceleration if the surge tank coolant level registers as little as 1/2
inch below the "FULL COLD" mark when checked cold (coolant at 60 - 90 degrees F).
As a result of a low coolant level in the surge tank, movement of the coolant (slosh) can momentarily trigger the low coolant switch in the tank.
CAUSE:
Low coolant level can result from the normal process of trapped air purging from the cooling system, a cooling system leak, and/or variations in
assembly plant fill.
CORRECTION:
In most cases, adding coolant to the surge tank to bring the coolant level one (1) inch above the "FULL COLD MARK" (when checked cold) will correct
this condition. However, be sure to visually inspect the cooling system for possible leaks. The system should also be inspected for any pinched, kinked
or improperly routed hoses or lines that could prevent a proper coolant fill.
After filling the surge tank as described above, verify correction by carefully driving the vehicle through a series of sharp left hand turns and/or by
making moderate vehicle accelerations. Should an intermittent low coolant light still exist, confirm that the low coolant switch in the surge tank is
operating properly. Refer to Section 6B of the service manual.
If the low coolant switch is confirmed to be operating properly and coolant level is correct, install a new surge tank, part number 22538029. Refer to
service manual Section 6B for surge tank removal and installation procedure.
NOTE:
The new surge tank incorporates a revised internal switch and float mechanism. The revised switch and float mechanism allows coolant level
in the surge tank to reach a point more easily distinguished as "LOW" when visually observed, before turning on the low coolant light. The
new surge tank was released to production and GMSPO in early September, 1989. Although a new part number was not released, the new tank
can be identified by a Julian Date code stamp of 2229 or greater. The date code is located on the top rear area of the tank.
Parts are currently available from GMSPO.
