my head gasket on my ute (a12) has gone. im sure heaps of people in here have done it before what is the procedure?

like the torque setting for head sutds?
tighting down sequence for head studs?

and any other suggestions or things to do?

CHEERS!

usually head is warped from heat causing head gasket to blow, take yours off and see if it isnt straight (put something flat accross its length)
if so just get another head, dont get yours machined (its cheaper unless youve got GX), make sure surfaces are very clean when putting new head on, theres one bolt that has to go back in number one position (in diagram)

someone else will give you settings and diagram for tightening cause they posted in a thread not long ago, or you could just search back

These are important:

- Take the head bolts out in the opposite of the torqueing pattern (see below)

- If you don't have a torque wrench, buy or borrow one. An inexpensive one will work, don't need a fancy ratchet type. If you don't use a torque wrench, there's a good chance the gasket will faill after driving it for a while, or the bolts break if you tighten too much.

- As mentioned, get the head and block surface clean (no grease, no tiny remnants of the old gasket). Use a scraper and maybe a little ether spray to chase it off. Make sure nothing gets in the cylinders or oil passages, and clean out the bolt holes when done. Oil or water in the bolt holes will prevent proper torqueing. You can use a straw to blow out the bolt holes.

- Check for straightness of the head. Often it won't need machining, even after a blown gasket, but you want to be sure. Place a quality straightedge across the head surface and use a feeler gauge to check any warp. The spec is that it can be up to 0.004 in. (0.1 mm). If it's over this, get the surface machined flat (milled). Keep in mind that the "normal" warp is up to 0.05 mm, so yes even new heads aren't perfectly flat. A good straight edge is a precision device, so you might have to round up an old mechanic friend or have a shop check it.

- don't use gasket sealer (according to my repair book and most gasket makers ...) unless your qasket maker specifically recommends it

- The oil bolt goes in Number One position (has a T mark, hollow head or is shaped differently)

- Generally, for any engine, tighten the middle bolts first, then work your way outside in a circular pattern, like this:

| 9 | 10|
| 5 | 6 |
| 1 | 2 |
| 4 | 3 |
| 8 | 7 |
__front__

Nissan's pattern is slightly different; this is the circular pattern.

This is done in three steps, my book doesn't say exactly what, so you can guess at the exact amounts, for example:
1. Tighten all 2/3 torque
2. Tighten all 80% torque
3. Final-tighten full torque

Torque specs (engine cold):

A12 33-36 ft-lb 4.5-5.0 Mkg (to engine # A12-470084)
A12 40-43 ft-lb 5.5-6.0 Mkg (from engine # A12-470085)
A14 51-54 ft-lb 7.0-7.5 Mkg

yeah thankx for that info great help! i will get to work on it soon!

i just spent 4 hours today on my sound syystem in my datto with a audio mate!

the system sounds wicked heaps a bass and loud!
I got pioneer 45x4 head unit, kenwood 6x9 3 ways in doors, sound stream 6inchs in kick pnaels, tweeters on dash and a Kicker impusle 2 way XI252 amp under seat. LOUD

i get my new seats in soon too.....! i will post some pics when i get them in

CHEERS

u should put these special subs or speakers under your seat you can buy them from jaycar and they have a metal cone inside instead of a normal one if that means any thing and it can put out a loud noise and cus of the metal cone i shakes like hell i say it he had it set up to juts ur average noise on some ####y r'n'b and you could fell it in the ground from the othger side of the store it was awsome they are a bit more costly then a normal speaker but its worth it

sounds good but the system i got is enough out the moment, hey it goes really hard and clear. the 6x9s amped out sound like subs there wicked.

hi guys,

im overhauling my a15.

its advisable not to use any headgasket sealer.

but ive seen some mechanic here using sealer like COPPER SPRAY , HIGH TEMP SILICON and even some use GREASE .

now im confused to use the sealer or not.

please advice guys...

If a special solid-copper head gasket is used, you must use the sealer. They are commonly used with extra high-boost tubercharging.

If a standard head gasket is used, no sealer should be applied.

Thin competition steel metal gaskets also require sealer.

Pay a mechanic there's no point in trying to be a hero you will save time money and effort in the long run.