Engine - Cylinder Head Bolt Tightening Sequence Revision
NO.: TSB-91-11-014DATE: October 1991
MODEL: 1991-1992 V6 DOHC Turbo Engines
SUBJECT:
6G7 TURBO-CHARGED ENGINE CYLINDER HEAD TIGHTENING - SERVICE MANUAL CORRECTION
PURPOSE
This bulletin revises the 1991 - 1992 V6 DOHC Turbo-charged engine cylinder head torque specification and the torquing procedure shown in the 1991 3OOOGT Service Manual and the 1992 Engine Overhaul Service Manual. Please make the indicated service manual corrections and as reference to this TSB please write this TSB number in the TSB Revision boxes on the affected service manual pages.
REVISED TORQUE PROCEDURE
In the illustrated sequence, torque all the cylinder head bolts in two or three stages to 125Nm (90 ft. lbs.), then loosen each bolt one by one, and finally re-torque it to 125Nm (90 ft. lbs.).
AFFECTED SERVICE MANUALS
1991 3000GT, Volume 1, Pages 11-23,11-34,11-39
1992 Engine Overhaul Service Manual, Pages 11E-21, 11E-95, 11E-99
TYPICAL SERVICE MANUAL CORRECTIONS
1992 Engine Overhaul Service Manual, Page 11E-21
As shown below cross out the "125, 90" next to the DOHC Turbo designation and write in "125 - LOOSEN EACH BOLT COMPLETELY ONE BY ONE - 125" and "90 - LOOSEN EACH BOLT COMPLETELY ONE BY ONE - 90".
TYPICAL SERVICE MANUAL CORRECTIONS continued
1991 3000GT, Volume 1, Page 11-39
1992 Engine Overhaul Service Manual, Page 11E-99
Write in "TURBO ENGINE -
1. TIGHTEN THE BOLTS IN TWO OR THREE STAGES IN THE ILLUSTRATED SEQUENCE.
2. LOOSEN EACH BOLT COMPLETELY, ONE BY ONE, AND THEN TIGHTEN IT TO THE SPECIFIED TORQUE."