How to: Cylinder Head Gasket Change

M20/M30/M50/Whatever! All engine related stuff here.
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Wed Oct 21, 2009 4:01 pm

I'll be starting this tonight! But I'll get a little list going of things that I remember now.

Things you'll need or possibly want to change while its apart:

T-belt & tensioner
Water Pump
Cam Seal
Head Set - Stay away from Victor Reinz.... They suck!
Head bolts - They are 1 time use only, these are a must!
Head studs - Only needed if you plan on boosting really.
Valve Cover gasket - Unless its included
Accessory belts - Might as well replace them while your at it
Starter - Much easier to get at if you want to replace it. Up to you though.
(2) bottles of 50/50
Oil filter and oil
Coolant hoses - Up to you really. I'd replace them if they haven't been, but that's just me.


Lets get started!

Step one: Follow the T-belt removal Write-up I did.

viewtopic.php?f=21&t=887

Step 2: Remove Valve cover. There are 8 10mm nuts that secure the valve cover to the head. Next unbolt the intake support bracket in the middle of the valve cover. Its mounted be 5 10mm bolts and should come right off. The last thing is to remove the vent tube. It should just be a little hose clamp and it should just slip right off. Then....with a little fangling it will come off.

Image

Image

Image

Image

Step 3: Unbolt the Exhaust Manifolds. I was forced to undo all the nuts the mount the manifold to the head. There about 10-12 of them and I think they are 11mm or 12mm nuts. Once those are unbolted, you should be able to push the manifolds out of the way. Otherwise, if you run into problems with the smaller bolts, you can undo the 6 13mm bolts that the exhaust bolts to the exhaust manifold. Those can be a pain though, so you might need a torch to free them up a bit.

Image

Step 3a: Remove Exhaust. This is optional, but if you want to you can. It is supported by a couple bolts near the rear of the trans and some hangers on the muffler

Image

Step 4: Drain coolant from the block. There is a large 19mm bolt on the side of the block, unscrew it. DON'T pull the plug out right away. Break it loose and unscrew it by hand. If you do this right, your floor will not look like a pool! Slowly unscrew it, when you start seeing coolant coming out, hold the plug again the hole and "direct" the coolant downward. If you just pull the plug out, it will shoot about 3ft out of the block....ask me how I know... :D

Image

Step 5: Disconnect the Throttle cable and Cruise control cable (Optional, See step 7)

Step 6: Remove IACV and Intake boot. The IACV is supported by a small bracket. It mounted to the intake by a 10mm nut.

Image

Step 7: Remove the throttle body. If you chose to leave the cables attached, then you'll just have to use a bungee cord or something to keep the stuff outta the way. This is what I did at least. :D Its got 4 10mm bolts the secure it to the intake. However, There are several hoses that will need to be looked at and removed. There are (2) small coolant hoses, (1) evap canister hose and (1) hose for the Crank Case vent. Remove the coolant and the crank case vent first, unbolt the throttle body but you should be able to leave the evap hose on. You can also just leave the cables on too. Once removed, just pull the stuff out of the way. However, youll have to unbolt a couple other things too like the throttle cable bracket and the dip stick tube.

Image

Bracket and dip-stick tube

Image

Step 8: remove brake vacuum lines; My 1990 IX and this IX are slightly different setup, but basically its all the same. Use a small flat head screwdriver that fits into the clip and pry it apart. Then pull the hoses off.

Image

Step 9: Undo the two wire harness clips underneath the t-body. They are only able to plug in to one spot, so don't worry about mixing them up.

Image

Step 10: Unbolt the Central Harness plug on the front of the motor.

Image

Step 11: Undo Fuel Lines. Obivously don't be a dumbass and smoke near the lines or something. There are two lines, a infeed line and a return line. Mark them right cause you don't want them getting mixed up. Carefully pull them off. Also, check for any cracking in the line itself. If there is any, replace the line.

Image

Step 12: Unplug the main Fuel Injector Plug. Its located underneath the intake on a bracket. It should just unscrew.

Image

Step 13: Unbolt and remove the Support bracket. Its underneath the intake where the injecter plug is held. You may have to cut a couple zipties, but it needs to be free from everything.

Image

Image

Step 14: Unbolt all the Cooling pipes going to the T-Stat housing. There's several of them so mark them as well

Image

Image

Step 15: Undo the Heater core lines. Mark these as well. You don't want to put them in backwards too... I'll have to get a pic later.. :(

Step 16: Unbolt head. There are 14 bolts securing the head to the bolt. They use a e14 external cap screw. To unbolt it, start in the middle of cylinders 3 & 4 and work your way out.

Here is the pattern:

14 10 6 2 4 8 12

11 7 3 1 5 9 13

Image

Step 17: Remove head. The whole thing should be good to come off now, but be careful. Trying to lift the whole thing off by yourself can be hard. It probably weighs about 100lbs all together which might not sound like much, but trying to lift it over the edge of a car can be really hard on your back. Have a friend help if need be. Before you pull it off, make sure you know where you are going with it. You have to find something to support the ends with that will be tall enough to clear any valves that may be open. DO NOT just put it flat on the ground....you can damage valve and scratch the mating surface all to hell. Slowly lift the assembly off while making sure that your not caught on anything. Once your clear, set it down....take a breath and be happy you have it all off! :D

Step 18: Inspect the Cylinders for any scoring or access wear. For my motor, I was pretty surprised to still see the cross hatching from the honing process 225,000 miles ago.. Not bad huh.

Image

Image

Image

Step 19: Clean the Head of any left over gasket material. I used a razor blade and alot of patience to do this. You must get all or as much as you can of the old gasket material. However, you must be careful as not to scratch the surface of the block. Any deep scratches may compromise the sealing capability of the gasket. Also... do NOT use a razor blade to clean off the head. Aluminum is softer than steel and therefore will the razor will easily scratch it. Instead, you can clean it with a solvent of some kind, or do as I did and get the head hot washed. It will clean the entire and it should be good to go. Also, with the head off, you may want to have the head machined flat if it is warped. Have someone check that out for you if necessary. I would have this done if the motor was over heated. Also, inspect the entire head for any cracks. These heads are pretty susceptible to cracks so look very closely.

Image

Step 20: Reattach the Intake Mani. Reinstall the manifold with new gaskets. Do not reuse old gaskets. They get torqured to 33ft#

Image

Step 21: Set Cam and Crank to TDC. To set the cam, turn the cam to the timing mark in the head. To set the crank, turn the crank so that piston 1 is at the top of its stroke. This should be TDC for both. Here is a pic of the Cam timing mark.

Image

Step 22: Place new head gasket on the block. Insure that the block is dry and oil free. Also, make sure that all the taps in the block are free of debris and that there is no oil or whatever in the bottom. This is very critical. Oil in the bottom can cause issues when tightening the head bolts... :D

Step 23: Place cylinder head on block. I suggest you get a friend to help with this step. The head is relatively heavy and cumbersome so placing it right might be a pain. You also need to be careful to watch the crank case vent tube. It needs to align with the hole in the intake manifold.

Image

Vent tube

Image

Step 24: Thread new head bolts in. When you thread them in, you need a little oil on the threads of the bolts to maintain a even torque. Don't douse them in oil...you don't want the excess oil falling into the bottom of the hole and screwing up the torquing proceedure.

Image

Step 25: Torque down head bolt to spec. Torque specs are 22ft# --> 90* --> 90* on all the bolts. There is no waiting between each torque.
The bolts head are torx bits and use a e14 socket. They are quite difficult to turn on the last phase, but thats normal

Image
Last edited by ten2doyle102 on Wed Dec 02, 2009 7:50 pm, edited 5 times in total.
Image
User avatar
M20_fever
Größter Vorsitzender
Posts: 11026
Joined: Fri Feb 27, 2009 1:28 pm
AntiSpam: No
Location: Northern IL

Re: How to: Cylinder Head Gasket Change

Postby M20_fever » Wed Oct 21, 2009 6:10 pm

on a roll!
Image
Midwestern Councel C Prepared class champion 2012
North Suburban Sports Car Club C Prepared class champion 2012
HSAX Instructor

GET YOUR E3P GEAR HERE: http://www.cafepress.com/e3pgearshop
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Wed Oct 21, 2009 6:20 pm

Yep... I'll try to get pics tonight. Hopefully I can work on it... but I do have some homework that i have been slacking on...
Image
User avatar
M20_fever
Größter Vorsitzender
Posts: 11026
Joined: Fri Feb 27, 2009 1:28 pm
AntiSpam: No
Location: Northern IL

Re: How to: Cylinder Head Gasket Change

Postby M20_fever » Thu Oct 22, 2009 12:41 pm

homework is the #1 reason I have no time to work on anything, 8 more months and I'm finally done.
Image
Midwestern Councel C Prepared class champion 2012
North Suburban Sports Car Club C Prepared class champion 2012
HSAX Instructor

GET YOUR E3P GEAR HERE: http://www.cafepress.com/e3pgearshop
User avatar
Yoshi
Site Admin
Posts: 9087
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: How to: Cylinder Head Gasket Change

Postby Yoshi » Thu Oct 22, 2009 12:51 pm

that head is so oil stained.. someone didn't change the oil AT ALL.

IMO, I keep the headers and intake manifold on and have a friend help me lift the head out (or pull my back doing it myself). Makes it easier

edit: and yes, manifold bolts are 12mm.
Image
Status: HG repair. 488wtq though!
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Thu Oct 22, 2009 1:42 pm

Yeah, I am going to leave the intake on this time, but the headers are such a bitch to get at from the bottom.. I'll see if I can get the nuts on the bottom to loosen.

I think that the combination of the car sitting for 4 years and that is has 225,000 miles let to the coloring of it. The cam is actually VERY nice and has practically no wear. Also, I change the oil in my red IX almost every 2,500 miles cause I drive it a bit hard... :D and I use valvoline vr1 racing oils. It too has some staining starting too.
Image
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Thu Oct 22, 2009 1:43 pm

M20_fever wrote:homework is the #1 reason I have no time to work on anything, 8 more months and I'm finally done.


Meh....it can wait another night... Jess is working all day and night so I am going to try to get the head off. Wish me luck!
Image
User avatar
Yoshi
Site Admin
Posts: 9087
Joined: Thu Feb 26, 2009 7:47 pm
AntiSpam: No
Location: North VA
Contact:

Re: How to: Cylinder Head Gasket Change

Postby Yoshi » Thu Oct 22, 2009 1:52 pm

I dunno... 4 door had 240k on it and it looked much less dark than that.
Image
Status: HG repair. 488wtq though!
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Thu Oct 22, 2009 2:02 pm

I guess its different for every motor. I don't know! :) LOL. I do know that this cam and stuff looks in great shape though. Has less wear than the cam that was in the old head from my red IX and that only had 170k on it when the rockers broked.


I think with a good cleaning and new gaskets, this motor should run pretty strong.
Image
User avatar
M20_fever
Größter Vorsitzender
Posts: 11026
Joined: Fri Feb 27, 2009 1:28 pm
AntiSpam: No
Location: Northern IL

Re: How to: Cylinder Head Gasket Change

Postby M20_fever » Thu Oct 22, 2009 2:49 pm

the head in my car had 153k on it when I rebuilt the engine and it was pretty clean inside, but the valve springs where about 8lbs under spec, had to shim them to get back to factory spec. I guess it just depends on what oil was used how often it was changed, etc...
Image
Midwestern Councel C Prepared class champion 2012
North Suburban Sports Car Club C Prepared class champion 2012
HSAX Instructor

GET YOUR E3P GEAR HERE: http://www.cafepress.com/e3pgearshop
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Sun Oct 25, 2009 6:13 am

Head is off! :)
Image
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Mon Oct 26, 2009 2:02 am

On further insepction of the cylinders... I found this..

Image
Image
User avatar
nogapersnBMWs
I <3 E30's
Posts: 136
Joined: Sat Sep 12, 2009 5:37 am
AntiSpam: No
Location: Denver and Dillon Lake, Kolorado

Re: How to: Cylinder Head Gasket Change

Postby nogapersnBMWs » Mon Oct 26, 2009 2:10 am

^^^^^. Nice work. Cylinder #6 looks baked though! Haha. Keep it goin'...:lol:
User avatar
ten2doyle102
I <3 E30's
Posts: 5462
Joined: Fri Feb 27, 2009 5:17 pm
Location: Appleton, WI
Contact:

Re: How to: Cylinder Head Gasket Change

Postby ten2doyle102 » Mon Oct 26, 2009 2:26 am

I found a little spotting at the top lip of a few cylinders, but all in all, it was pretty clean yet. Ordered a new Head gasket yesterday.
Image
User avatar
nogapersnBMWs
I <3 E30's
Posts: 136
Joined: Sat Sep 12, 2009 5:37 am
AntiSpam: No
Location: Denver and Dillon Lake, Kolorado

Re: How to: Cylinder Head Gasket Change

Postby nogapersnBMWs » Mon Oct 26, 2009 4:38 am

ten2doyle102 wrote:I found a little spotting at the top lip of a few cylinders, but all in all, it was pretty clean yet. Ordered a new Head gasket yesterday.


Warp speed Captain...
:D

Return to “Engine”

Who is online

Users browsing this forum: No registered users and 6 guests