924 Turbo Model

This technical information replaces all previous instructions concerning the tightening of cylinder heads on 924 Turbo vehicles produced from 1980 to 1982. The following parts are valid for repairs.

Cylinder Head Gasket

Part Number 931 104 337 03

Cylinder Head Bolt

Part Number N 014 731 2

Washer

Part Number 059 103 377 A

Tightening is done in 5 steps but not to the torque angle method:



Step 1: Tighten head bolts to 40 N-m (29 ft.
lbs.) following sequence.
Step 2: Tighten head bolts to 80 N-m (59 ft.
lbs.) following sequence.
Step 3: Tighten head bolts to 110 N-m (81 ft.
lbs.) following sequence.
Step 4: After at least 60 minutes, retighten
cylinder head bolts by first loosening No. 1 bolt (see sequence) by 1/2 turn and then retightening to 110 N-m (81 ft. lbs.) Apply procedure to remaining bolts in sequence.

Run engine to operating temperature (oil temp. approx. 80~C).
Step 5: Let engine cool down and tighten cylinder head bolts as in Step 4.

Note: Cylinder head bolts do not have to be retorqued. Threads and bearing surfaces of bolts must be lightly lubricated with oil prior to installation. Washers must not turn while tightening. Create a reference mark if necessary. Cylinder head bolts of this type can be reused.