PDA

View Full Version : Head bolt torque sequence



gakare
07-21-2009, 10:10 PM
I am replacing the head gaskets on my 2003 Impreza 2.5, SOHC. The service manual I have shows the following:

(1) Apply a coat of engine oil to washers and
bolt threads.
(2) Tighten all bolts to 29 N.m (3.0 kgf-m, 22 ft-
Ib) in alphabetical sequence.
Then tighten all bolts to 69 N.m (7.0 kgf-m, 51 ft-
Ib) in alphabetical sequence.
(3) Back off all bolts by 180" first; back them off
by 180" again.
(4) Tighten the bolts (a) and (b) to 34 N-m (3.5
kgf-m, 25 ft-lb).
(5) Tighten the bolts (c), (d), (e) and (f) to 15
N.m (1.5 kgf-m, 11 ft-lb).
(6) Tighten all bolts by 80 to 90" in alphabetical
sequence.
CAUTION:
Do not tighten the bolts more than 90".
(7) Further tighten all bolts by 80 to 90" in alphabetical
sequence shown in the figure below.
CAUTION:
Ensure the total "re-tightening angle" [in the
former two steps], do not exceed 180".

Seems quite involved. Can anyone verify that this info is correct?