Hi I kneed the torque spec'a and sequence for the head's on 3100 searies 1999 buick century engine and the plenum thanks

https://www.fixya.com/cars/t22804106-torque_specifications

https://www.fixya.com/cars/t13126328-
torque_specs_head_bolts_2002_buick

https://itstillruns.com/34l-torque-specs-7612234.html

https://itstillruns.com/gm-3100-torque-specifications-7523925.html

1st you need all new head bolts, do you have them?

You can usually just call a parts store and have them give you the sequence and torque specs over the phone. Most lead counter persons know how to look this up. The Chilton`s books will also have this info on your specific vehicle.

hope this helps,

Torque sequence --------- front ' 6 1 3 7 ' of ' ' engine ' 8 4 2 5 ' --------- Step 1: torque bolts in sequence to 37 Ft/Lbs Step 2: torque all bolts in sequence an additional 120 degrees Step 3: torque bolts 1,2,3, & 4 an additional 30 degrees recheck final torque in sequence *** CAUTION ***engine uses Torque To Yield head bolts (TTY) thatpermanently stretch during the initial installation.New head bolts must be used when cylinder head isreplaced or re-installed to obtain proper torque.
always torque from center
Tighten each bolt an additional 90° in sequence.

Fig. Cylinder head bolt tightening sequence-3.1L engines & 2001-04 3.4L engines




Fig. Cylinder head bolt tightening sequence-2005 3.4L engines



Hope this help (remember rated and comment this).

Exhuast manifold torque 38 foot pounds, Head bolts are 38 Foot pounds after you add sealant to the bolts then after torque go another 130 degrees. Tighten center 4 bolts in sequence another 30 degrees.

Head Torque sequence Step 1: torque to 50 Ft/Lbs Step 2: torque to 105 Ft/Lbs recheck final torque in sequence.

Torque intake manifold: Step 1: 12 inch/Lbs, (hand tight) Step 2: 72 inch/Lbs, (6) Ft/Lbs Step 3: 12 Ft/Lbs
torque intake plenum: Step 1: 24 inch/lb (hand tight) Step 2: 48 inch/lb (4) Ft/Lbs Step 3: 84 inch/lb (7) Ft/Lbs (To torque bolts, start in center using crisscross pattern)

hi bob
head torque on the 2.0 DOHC is 64 ft lbs , done in two -three steps , also there is a sequence for proper order . here is a very good description with graphics .

1999 kia sportage 2.0 DOHC head torque

Thanks for using FIX YA !

J5