How To Change a Head Gasket

Heres a step-by-step walk-through of how to change a Head Gasket on your Honda's D-series motor. And btw, sorry for some of the blurry pics... I'm not a photographer

1. Start unplugging wires and hoses. Everything attached to the head from the car's body or the block MUST be disconnected.

2. Unbolt your header. I had to pull out my A/C fan to get it to clear the studs on the block.

3. IMPORTANT STEP! Set your motor to TDC (Top Dead Center), where the #1 cyl. is on the Intake stroke. Post if this confuses you.

4. Remove the timing belt. I just slide mine off. Remember NOT to turn the motor OR the Cam-gear after this step, unless you like head-aches.

5. Unbolt your head bolts in sequence. Make sure you have a manual in front of you, and unbolt in 1/4-turn increments until you can looses them by hand. Your Manual tells you all of this. GET ONE.

6. Keep track of what bolts go into what hole. I used stickey notes.

7. Head bolts removed.

8. Head removal. This is easier with two people. I did it by myself. I'm a framer and have a strong back, and my back still didn't like me after this.
Notes: Just make sure you don't force it. take your time. double and triple check for coolant lines. make sure the PCV valve hose is pushed out of the IM.

I thought it was kinda funny...

And the engine after the pull:

9. This is where I grabbed a water, wiped down all the oil on the car/floor/pants/desk, then just looked over my pistons.
Notes: Just take a Shop Vac and stick it on the pistons, just to make sure theres no grease/dirt/oil on them.

10. Moving onto the head, after draining the oil on/in it (by just turning it upside down over an oil pan), I took off the TB and IACV to clean them. My IACV is going out, so I figured I'd help it out a bit by cleaning the screen on it. it can't hurt. The TB I just took off for kicks and to clean it out/check out what the inside of my IM looks like (yikes! )

11. Then I checked out my valves. just looking them over and cleaning them up with a shop towel.
Notes: Just take care when you flip up the head/IM, as there are a couple sensors and plugs that you could break in doing this. just a friendly reminder.

12. This is where I started cleaning up everything. Degreaser, followed by a toothbrush scrub, then a wipe-down with a clean Paper Towel worked Awsome for me.

Installation

13. Important! CLEAN the block's deck to make sure theres no dirt or grease where the new HG will sit. Then go ahead and set the new HG down and line it up.

After numerous failed attempts to get everything to line up, I devised a way to keep the HG in place, as well as a way to guide the Head right down on to the block- PENCILS!. Yep. They worked great!
Notes: Make sure you feel the metal dowels set into place from the Head to the Block. I believe there actually oil passages, but dowels might be more easily understood.
Also, if you desire, now is a good time to go ahead and set that Clutch cable behind/under the IM, just to give you that clean, 'wired tucked' look, if your into that sort of thing.

14. Soak the bolts in regular 'ol motor oil for a few seconds before screwing them down.
Notes: As you put them in, go ahead and take your rachet/socket/extention and tighten them only until SNUG, then move on to the next one.

15. Begin your torque'ing sequence. Remember to torque the bolts in two stages, as noted in your Manual. In my case(and most D-series cases), you torque them all to 22ft-lbs, then follow that up with 53ft-lbs. Just make SURE to follow the torqueing sequence so-as to not warp the head.

16. Start connecting coolant lines, wiring harness connections, and then re-install the timing belt etc.

Then your done!

Hopefully this'll help someone out there looking to try this out by themselves.
Mods & Admins, your more than welcome to move this thread into any 'restricted forums', that normal members can't post in, if you think it'll help out the site.

Comments Welcome!!!

-Andrew

 

[Remedy]

anti sieze is a much better choice than oil

There are 2 kinds of torque spec generally published in the shop manual, dry fastener and oiled. When the manual calls for oiled they mention 30wt motor oil. Antisieze reduces friction which alters the amount of twisting force you can apply to a fastener. You will over torque your bolts, they may snap or they may not. Your HG may be crushed too much, or not. I had a rep from a fastener mfr come to speak to a class and he stood right there and told us to reduce torque by approx 20% when using antisieze. While I agree with your statement that in certain cases antisieze is better, I would limit it to exhuast bolts and spark plugs myself.

Nice pictures by the way... it looks so easy but I remeber it being something of a PITA. I took my head in for testing/surfacing because I don't have a crystal ball to tell me if I will have to buy a new head and do the job again next week. I have done three heads now and so far I had one cracked... it was an iron head though.

 

[gablagloire]

How about for a b16a3 engine? Is it much different than your writeup? If i were to follow this writeup, will i be sucessfull?

 

[Andrew]

it will not be the same(as in exactly like I did it), but it's the same process.
Disconnect fuild lines and harness
unbolt header
*in the case of it being DOHC* you'll have to pull the cams
etc.

but as far as the priciple, yes, it's the same. it's just a little different setup on the dual cams.

 

[welfare]

You actually missed one very important step. . .
once you drain the coolant there is still some in the block so when you take the head off it goes everyehere (like in your pics)
Not only does it go in the clyinders, but it also goes in the holes in the bolck where the headbolts go.
From experience if you don't/can't drain the engine block you should clean out the headbolt holes because when you put everything back together the headbolts will push coolant back out of the holes, it will end up between the head and the bolck, where the headgasket is, and when you go to torque it down it won't be torqued correctly, there will be a gap where the coolant is (liquid cannot be compressed). This will cause the headgasket to fail again prematurely.
I had this happen to me on the very first headgasket I changed, like 8 years ago. Ever since I make sure!


Also, like remedy said coating the bolts in oil or some sort of lubricant is reccomended due to correct torque measurements. It takes more torque to tighten a bolt that has no lube as opposed to a bolt that does.
That is why ARP studs come either pre-lubed or with thread lubricant, so that a proper torque can be achieved. Ask any engine builder.

Excellent writeup nonetheless

 

[welfare]

Also, it is recommended that you replace the headbolts after you remove them, but I have also seen the re-used with no problems.

 

[Andrew]

You actually missed one very important step. . .
once you drain the coolant there is still some in the block so when you take the head off it goes everyehere (like in your pics)
Not only does it go in the clyinders, but it also goes in the holes in the bolck where the headbolts go.

Also, like remedy said coating the bolts in oil or some sort of lubricant is reccomended due to correct torque measurements. It takes more torque to tighten a bolt that has no lube as opposed to a bolt that does.

Also, it is recommended that you replace the headbolts after you remove them, but I have also seen the re-used with no problems.vv

Excellent writeup nonetheless

Thanks for your imput bro!

In that case I guess I got off easy, because I didn't have any problems with coolant in the bolt holes, and very little on the pistons(which were all cleaned out btw, I just didn't show the reinstall.

I did soak them in oil. didn't you see?

And lastly,

Honda DOES tell you to replace the bolts when you remove them, but many people reuse them without a problem.

Thanks for re-enforcing that point!

Again, I appreciate your imput. every little tid-bit helps

 

[posol]

no posts in a while, time to archive this in the general tech articles
Thanks Andrew