Skyhawk L4-121 2.0L VIN K TBI (1987)
Turbocharger Coolant Line: Technical Service Bulletins
Turbocharger - Cooling Line Size Change
Bulletin:
87-6B-3
Date:
Aug., '88
Ref. No.:
87-232-6B
Corp. Ref. No. 836205
SUBJECT:
TURBOCHARGER COOLING LINE SIZE DIFFERENCES
MODELS AFFECTED: 1987 SKYHAWKS WITH 2.0L OHC TURBO ENGINES (VIN CODE M)
During the mid-1988 model year, the L-4 turbocharger applications changed the size and material of the turbo water feed pipe. The feed pipe diameter
reduction change (1/2" to 5/16") does not impact turbo cooling efficiency; however, the pipe material change (stainless to carbon steel) improves sealing
ability after any repair in this area.
For 1988 vehicles, the turbo cooling feed pipe from thermostat to turbo center housing should be checked for size before ordering any parts from
GMSPO. The 1987 L-4 turbocharger system uses the 1/2" cooling line, but it can be serviced with the mid 1988 5/16" line and other parts, if improved
coolant line sealing is necessary.
Following is a detailed breakdown of the specific parts required:
1/2" 1987 and Early 1988
-
Thermostat Housing Assembly - Part Number 10045025.
-
Housing attachment torque is 12-18 N-m (9-13 ft.lbs.).
-
Turbo Coolant Feed Hose Assembly - Part Number 10045022.
-
1/2" line nut torque is 40-50 N-m (29-37 ft.lbs.).
5/16" Mid-1988 System and 1988/87 Back Service Group
-
Thermostat Housing Assembly - Part Number 10068533 or 10116222
-
Thermostat Housing Gasket - Part Number 10103540.
-
Housing attachment torque is 12-18 N-m (9-13 ft.lbs.).
-
5/16" Turbo Coolant Feed Pipe Assembly - Part Number 10068531.
-
5/16" line nut torque is 15-20 N-m (11-16 ft.lbs.).
-
5/16" Turbo Center Housing Fitting - Part Number 10121014.
-
Fitting install torque is 30-45 N-m (22-33 ft.lbs.).
