2.5 Head Bolt Torque

[Phillip]

I've got two service manuals (Haynes & Motors) that have conflicting head bolt torque specifications. After tightening to 22 ft. lb, then 51 ft. lb., back off 180 degrees, then back off another 180 degrees, torque center bolts to 25 ft lb and outside bolts to 11 ft lbs. (both manuals agree to this point).

 

Haynes says to turn all bolts 180 degrees then turn all bolts another 180 degrees.

 

Motors says just turn the bolts 180 degrees once.

 

I'd sure hate to do this incorrectly - can anyone tell me the proper procedure? Thanks in advance.

 

.

[theotherskip]

use a marker to mark the heads of the bolts at 12 o'clock. this will help you keep track of the angles. when you back them out 180deg then 180deg again, they will be loose.

 

from factory service manual:

 

Tighten cylinder head bolts.

(1) Apply a coat of engine oil to washers and bolt threads.

(2) Tighten all bolts to 29 N⋅m (3.0 kg-m, 22 ft-lb) in numerical sequence.

Then tighten all bolts to 69 N⋅m (7.0 kg-m, 51 ft-lb) in numerical sequence.

(3) Back off all bolts by 180° first; back them off by 180° again.

(4) Tighten bolts 1 and 2 to 34 Nm (3.5 kg-m, 25 ftlb).

(5) Tighten bolts 3 , 4 , 5 and 6 to 15 Nm (1.5 kg-m, 11 ft-lb).

(6) Tighten all bolts by 80 to 90° in numerical sequence.

CAUTION:

Do not tighten bolts more than 90°.

(7) Further tighten all bolts by 80 to 90° in numerical sequence.

CAUTION:

Ensure that the total “re-tightening angle” [steps (6) and (7) above] do not exceed 180°.

 

bolt 1 is middle top

bolt 2 is middle bottom

bolt 3 is left top

bolt 4 is right bottom

bolt 5 is left bottom

bolt 6 is right top

[Phillip]

Thanks for the quick response! With any luck, I'll have the new engine in and running late today.

[incognito]

You bought a new 2.5? How many miles was the old one at?

[Phillip]

The engine failed at 91,000 miles. I bought the car with the engine knocking badly. Neither the crank nor 2-rods were salvagable. I can hardly believe how much used engines cost; I paid $1,200 for a new short-block from Subaru. With gaskets, oil pump, valve grind, etc., I'll have about $1,700 in it. The cheapest used engine I found had 95,000 miles on it and was priced at $1695 + freight! The old engine was full of sludge, especially the PCV system (it was totally plugged); I suspect the oil hadn't been changed in a very long time!

[incognito]

Greeeat... Im about to roll up on that milage with the same situation. (bought car knocking badly, was due to ignition problems. )