Cracked Block & Engine Repair Procedure
FIGURE 1:
CRACKED BLOCK PROCEDURE
1. Pressure test for evidence of coolant loss.
2. If pressure test shows no visible evidence of coolant loss, remove cover from valve lifter area and inspect casting above lifter cavity (see Figure 1).
3. With engine warm and pressure applied, coolant should be visible using a "black light."
4. If condition is evident, cylinder block and those associated parts identified in this bulletin must be replaced using applicable replacement procedures referenced in Section 6A of the 1986 Fiero Service Manual. To prevent camshaft lobe and valve lifter scuffing, use Engine Oil Supplement P/N 1052367 (16 oz.).
ENGINE REPAIR PROCEDURE
Repair rod knocks by performing the following procedure:
CAUTION: PROPER SERVICE PROCEDURES AND SAFETY PRACTICES, AS DESCRIBED IN THE REFERENCED SERVICE MANUAL, MUST BE FOLLOWED. FAILURE TO FOLLOW PROPER SERVICE PROCEDURES, INCLUDING ALL SAFETY PRECAUTIONS, COULD CREATE CONDITIONS THAT MAY LEAD TO ENGINE COMPARTMENT FIRES, POSSIBLY CAUSING INJURY TO PERSONS SERVICING AND/OR OPERATING THE VEHICLE.
A. Remove oil pan.
B. Remove connecting rod caps.
C. Remove main bearing caps.
D. Measure connecting rod and main bearing clearances and crankshaft connecting rod journal and main bearing journal diameters, per 1986 Fiero Service Manual, Section 6A-10 through 6A-13.
E. If bearing clearances are excessive and none of the bearings have spun, install a new set of rod and main bearings, per 1986 Fiero Service Manual, Section 6A10 through 6A13. If necessary, replace crankshaft. DO NOT INSTALL A REMACHINED CRANK!
FIGURE 3:
E. (Cont 'd.)
If cylinder head removal is necessary, replace all cylinder head bolts with new SAE grade 11.9 bolts. The bolt P/N 's are shown below:
SAE Grade
Bolt Position 11.9 Bolt P/N
1-8 10044566
9 10044568
10 10044570
Head bolt tightening procedure is as follows:
- Clean bolts and head spot faces.
- Oil bolts with engine oil (5W-30).
- Apply sealing compound (P/N 1052080) to threads of bolts # 9 and # 10.
- Install cylinder head with new head gasket (P/N 10043091) and finger start all head bolts.
- Torque all head bolts to 25 N-m (18.5 ft.lbs.) in sequence specified in Figure 3.
- Repeat sequence, bringing torque to 35 N-m (26 ft.lbs.) on all bolts except # 9. Retorque bolt # 9 to 25 N-m (18.5 ft.lbs.)
- Repeating same sequence, rotate all ten head bolts 90 degrees.
NOTE: Refer to 1986 Fiero Service Manual for proper fastener torque specifications.
F. Install a new oil pan (P/N 10035817, order from GMSPO), per 1986 Fiero Service Manual, Section 6A1-14.
G. Change oil and oil filter. Install AC type PF-51 oil filter P/N 25010908. Install 4.0 quarts SF grade 5W-30 engine oil. Replace old dipstick with new recalibrated dipstick P/N 10101497. Check for proper engine operation and verify that no oil leaks exist following repairs. It is recommended that a black light be used to detect oil leaks per 1986 Fiero Service Manual, Section 6-5, correct as required.
Upon Completion of engine repair, check for oil and coolant leaks by performing steps 2A, 2B, and 2C and continue with balance of service repair procedures.
If the above repair procedure is inadequate to restore proper engine operation (engine severely damaged) follow appropriate steps to install a short block assembly as described in Pontiac Dealer Service Management Bulletin 84-SM-34C.
CAUTION: PROPER SERVICE PROCEDURES AND SAFETY PRACTICES, AS DESCRIBED IN THE REFERENCED SERVICE MANUAL, MUST BE FOLLOWED. FAILURE TO FOLLOW PROPER SERVICE PROCEDURES, INCLUDING ALL SAFETY PRECAUTIONS, COULD CREATE CONDITIONS THAT MAY LEAD TO ENGINE COMPARTMENT FIRES, POSSIBLY CAUSING INJURY TO PERSONS SERVICING AND/OR OPERATING THE VEHICLE.