Hello, what is the torque spec for the exhaust manifold to cyl. head nuts on a 2004 toyota sienna v6?

20. INSTALL CYLINDER HEAD COVER SUB-ASSY
(a) Apply seal packing to the cylinder head as shown in the
illustration.
Seal packing: Part No. 08826-00080 or equivalent
NOTICE:

Remove any oil from the contact surface.

Install the cylinder head cover within 3 minutes after
applying seal packing.

Do not start the engine within 2 hours after installing.
(b) Install the cylinder head cover with the 9 bolts. Tighten the
bolt uniformly in several steps.
Torque: 8.0 Nm (80 kgf cm, 71 in.lbf)
(c) Install the engine wire harness with the 3 nuts.
Torque: 8.4 Nm (85 kgf cm, 74 in.lbf)
21. INSTALL CYLINDER HEAD COVER SUB-ASSY LH
(a) Apply seal packing to the cylinder head as shown in the
illustration.
Seal packing: Part No. 08826-00080 or equivalent
NOTICE:

Remove any oil from the contact surface.

Install the cylinder head cover within 3 minutes after
applying seal packing.

Do not start the engine within 2 hours after installing.
(b) Install the cylinder head cover with the 9 bolts. Tighten the
bolt uniformly in several steps.
Torque: 8.0 Nm (80 kgf cm, 71 in.lbf)
(c) Using an E6 torx) socket wrench, install the engine wire
harness protector with the 2 bolts.
Torque: 8.4 Nm (85 kgf cm, 74 in.lbf)

This is year/make/model specific to the 2nd Gen Sienna. Taken from the 05 Toyota Sienna repair manual. Hope this answers your torque specs for the valve covers which uses 10 mm bolts. If in doubt, as Scotty Kilmer asserts, do a "German tight".

Install the cylinder heads. Use new gaskets and tighten the bolts, in sequence, as follows:

1. Step 1: Bolts 1-8 to 20 ft. lbs. (27 Nm)
2. Step 2: Bolts 1-10 verify torque without loosening
3. Step 3: Bolts 9-12 to 10 ft. lbs. (14 Nm)
4. Step 4: Bolts 1-8 plus 1 / 4 (90 degree) turn
5. Step 5: Bolts 9-12 to 19 ft. lbs. (26 Nm)

sensor a will be the one closest to the exhaust manifold on the engine block bank 2 is, well if you look closely at the engine on a v6 , bank one, the first cylinder is just slightly ahead of the first cylinder on the opposite side .

normal torque specs for wheel nut is 110 NM

Spark plug torque on the 3.0L engine is 13 ft.lbs. and the 3.3L is 18 ft.lbs.

Valve covers-69 inch lbs.

Intake Manifold-11 ft. lbs.

cylinder head and main bearing bolts had a first step torque of 50 to 60 foot-pounds and a second step torque of 80 to 90 foot-pounds each. The rod bearing bolts had a first step torque of 25 to 30 foot-pounds and a second step torque of 30 to 36 foot-pounds. The intake manifold and exhaust had a first step torque of 5 to 7 foot-pounds. The intake manifold had a second step torque of 14 to 21 foot-pounds while the exhaust manifold had a second step torque of 16 to 23 foot-pounds.

BMW PARTS

Install the cylinder head bolts. Starting at top center, tighten all cylinder head bolts in sequence as shown in illustration, using the Cylinder Head Bolt Wrench (09221 - 32001) or equivalent. Repeat the procedure, re-tightening all cylinder head bolt to the specified torque. (torque spec is Cold Engine 105-115 Nm (76-83 ft lb) )
. Install the timing belt tensioner pulley.
. Install the timing belt on the camshaft sprocket, making sure that the tension side is tightened by turning the camshaft sprocket in reverse, all timing marks are in alignment.
. Adjust the timing according to "Timing Belt"
. Install the rocker cover and tighten the bolts to the specified torque. Tightening torque: Rocker cover belt:

2.5-3.5 Nm (25-35 kg.cm, 2-3 ft. lbs.)

. Install the timing belt cover.
Install the new intake manifold gasket and the intake manifold. Tighten the nuts and bolts to the specified torque.
Install the new exhaust manifold gasket and the exhaust manifold. Tighten the exhaust manifold attaching nuts to the specified torque.
. Install the surge tank and tighten the nuts bolts to the specified torque.
. Install the power steering oil pump and bracket.
. Install the ignition coil.
. Install the air intake hose.
Connect the vacuum hose, fuel hose and water hose.
. Install breather hose.

Fig. Left side exhaust manifold bolt torque sequence-3.0L engine




Fig. Right side exhaust manifold bolt torque sequence-3.0L engine

Both cases, exhaust manifold and new gasket, torque the bolts to 15 ft. lbs. (20 Nm).

Good luck (remember to rate this answer).

heres the torque specs and the way to tighten the head bolts for your 1998 toyota sienna, hope this helps,
12 point bolts step 1- 40 ft lbs
step 2- additional 90 degrees
recessed bolt 13 ftlbs

Assuming 3.0 V6, per my manual:

All in FT pounds torque,unless noted:

Main bearings: 60
Connecting rod bearing cap nuts: 34
Rocker arm shaft bolts 180 INCH POUNDS
Intake manifold: 168 INCH POUNDS
Exhaust manifold nuts: 18
Crankshaft vibration dampner bolt: 112
Cam shaft sprocket bolts: 70
Head bolts: 76 - 83
If you need others please let me know, when working with Aluminum parts go easy as they can strip easy.
Please let me know if this helped,
Tom