request m20 headgasket replacement writeup?

[///M42 sport]

Any good links out there? or can someone do one? Thanks.

[whodwho]

The Bentley manual does a good how to ;)

[AnimalE30]

1. Drain coolant.
2. Remove rad/coolant hoses.
3. Remove headers.
4. Unplug vacume hoses/intake.
5. Remove intake manifold.
6. Remove head.
7. Replace head gasket.
8. Put everything back together.
9. Get ready for the next issue your m20 presents you.

But honestly, the only thing you really need to know is the loosening/tightening sequence for the head bolts. Other then that just keep taking shit apart until you get to the head.

[lolcantturn]

The first thing you need to do, if you are already, is to shut up, don't cry, and realize that replacing a HG is super easy, I swear. It shouldn't take you more than an hour to get the head off. It's literally nuts and bolts, there's no tricky parts. Just removing a bunch of nuts and bolts. That being said,
Off the top of my head, here are the tools you'll need:
Breaker Bar
17mm hex or E14 torx (depending on the headbolts on your car)
13mm, 12mm, 10mm, 7mm socket
1/4th drive ratchet for the harder to reach exhaust mani bolts
jumper wire
adjustable wrench. I think that's it off the top of my head.

BATHE your exhaust manifold bolts in PB blaster
Drain your coolant from the rad.
take distributor cap off, along with the rotor
take timing cover off
jump connections 11 and 14 on your diagnostic connector until the cam mark lines up to the mark on the head. This will manually jump your starter
loosen the tensioner with the 13mm. Kind of tricky at first but you'll get it
Take the timing belt off of the cam
loosen all the exhaust mani bolts. Slide the manifold off. It shouldn't be too difficult.
take off all the air intake stuff, air box, boot, ICV, vac lines to the throttle body
take off accelerator and cruise control cable
open up valve cover and loosen all the head bolts and take em off. At this point, you should be able to lift your head and intake manifold. This is where you disconnect anything else remaining, any electrical connection, and hoses. This is really straight forward.
Inspect and clean the head where the headgasket goes. Clean the long block where the gasket mates with the head.
Put head back on, you better have new headbolts. But wait, don't torque it down yet. Just finger tighten 2 head bolts in half way to make sure the head gasket won't move. This way, the HG won't move, but the head will still have a bit of play, which will come in handy in about a couple of sentences. Put the rear hose back on that came from the back of the head.
Make sure you have the bitch tube in the intake manifold well. take off the spring on the bitch tube and use 2 thin wires to keep it compress. Put the spring back on the bitch tube, and on the long block. Mount the intake manifold over the bitch tube (which is why we kept the head loose, so you can play around with the intake manfiold), and then cut the two wires which will uncompress the spring and tension it against the long block and the intake manifold. Make sure it's in there nice and tight.
Put the exhaust manifold back on. Now put the rest of your head bolts back on and torque to spec and in sequence.
Make sure your crankshaft is on the TDC mark. This is really the only annoying, tricky part. Slide the timing belt over the cam, making sure there is NO slack on the driver side of the belt. Tension it up. Using your adjustable wrench, open it up wide and rotate the big crankshaft bolt. It should be relatively easy to move if all your spark plugs are out. rotate your engine slow. Wait for the cam gear to do 360*, and match the cam gear's timing marks again. IF YOU FEEL ANY THING STOPPING THE ROTATION, stop! your valve is hitting your piston. If your cam gear is on the mark, and your crankshaft is on the mark, then you're good to go. If not, you're going to have to play around with the timing belt to make sure both the cam gear and crankshaft allign.
IT IS IMPERATIVE to hand crank the timing belt before starting the engine. The last thing you want is bent valve and rockers before you even get to use your new headgasket.
Connect everything, start your car. Bam.

It should take you less than an hour to take the head off, and about 2 hours to get it back on and running for a first timer. It is a super easy job in my opinion. Just tedious. You know when your teacher was absent and she left a bunch of busy work for the substitute? Kind of like that. Just imagine 100 math problems that you could solve easily, but was just tedious. That's how a head job is.

[whodwho]

I leave the intake and exhaust manifold on and pull as a unit.

[///M42 sport]

^^details?

Considering I've already replaced the manifold studs and header nuts just yesterday...it'll be super easy for me them remove again haha

But is there a freaking tool to tighten down the studs? Besides the 2 nut method?

BTW thanks for the responses so far!

[jlevie]

Close...

1. Drain coolant.
2. Remove rad/coolant hoses.
3. Remove headers.
4. Unplug vacume hoses/intake.
5. Remove intake manifold.
6. Remove head.

6a. Take the head to a machine shop and have it checked for warp or cracks. If warped, have the head surfaced. In most cases I'll have a minimum cut done on a head that has come off a running engine, just to be sure it is dead flat.

7. Replace head gasket.
8. Put everything back together.

8.a. You must use new head bolts and will need a new timing belt & tensioner

9. Get ready for the next issue your m20 presents you.

But honestly, the only thing you really need to know is the loosening/tightening sequence for the head bolts. Other then that just keep taking shit apart until you get to the head.

[browntown]

also, you might as well replace the timing belt and water pump if you're anywhere close to their replacement intervals.

[///M42 sport]

what else can I do maintenance wise while i'm in there?

Replace fuel injectors?
coolant lines?
heater core lines?

[slammin.e28]

what else can I do maintenance wise while i'm in there?

Replace fuel injectors?
coolant lines?
heater core lines?

If you want to, why not?

[matias88e30]

I leave the intake and exhaust manifold on and pull as a unit.

+1, easier and less work.

[EyExR]

Thread revival!

lolcantturn - Great write up!

Why do you need to jumper the diagnostic connector?

[vpilarrt]

Why do you need to jumper the diagnostic connector?

That was just to bump the starter to line up the timing marks. You do the same thing by turning the big crank bolt (remove spark plugs to make it easier).

[EyExR]

That was just to bump the starter to line up the timing marks. You do the same thing by turning the big crank bolt (remove spark plugs to make it easier).

oh, cool. Just jump it with a wire and toggle switch? That will make it much easier to get TDC and to do valve clearances in the future...

[frankie591]

if you pull spark plugs the motor turns over by hand very easily