mlm0

Just starting to replace head gaskets on 89 l98, stock

I am going to take my time, so this thread May last a while

First question, can I just unbolt exhaust manifolds and pull back out of the way to remove heads, or do I have to remove out of car completely

Reading the FSM, it does indicate that I have to use thread sealant on the head bolts, but I thought I read somewhere on this forum you did. Do I?

Be patient, lots more questions to come, and I am always open to suggestions for an easier way to do things

Hot Rod Roy

Your exhaust manifolds will still be securely attached to your exhaust pipes, so you won't be able to move them far enough to get access to the bottom bolts on your heads. The manifolds need to come out. (Remove spark plugs first.)

All of the head bolts go into the water jackets, so they all need sealant.

Rotate your crank to #1 firing position before you pull your distributor. Have fun, and pay attention to every tiny detail!

John A. Marker

with Hot Rod Roy, line up timing mark to fire on #1 with compression on #1 before pulling distributor. This will make it much easier for installation.

1) Label each bolt you remove, for example some are longer and some are shorter on the runners to the intake. Don't want to mix them up.
2) Label all wires, hoses and other parts you remove.....don't leave it up to memory. You will thank your self later when putting things back together. Take pictures or make drawings.
3) Some things, you don't have to remove....like the fuel rails and injectors...leave them. Just unfasten the lines at the front. Be sure that you have rubber plugs to slip over the lines running back to the tank. If you don't you will have fuel leaking all over.....NOT GOOD!!!
4) Leave all lines to air conditioning hooked up, just move things out of the way and tie or wire out of the way.
5) Drain block, pull the knock sensors. If you don't, you will have coolant in the cylinders and possibly in the oil when you remove the heads.
6) Always use anti-seize on bolts going into aluminum. Thread sealer on head bolts and intake bolts (where the bolt goes into the valley).
7) If you have a die grinder, consider gasket matching plenum to runners, runners to intake and intake to heads. Same for exhaust manifolds. Your not doing a porting job, just smoothing things out.
8) Consider taking a center punch and dimpling the china walls to give your silicone or "the Right Stuff" something to grab.


Good luck on your project.

ghoastrider1

use lots of Blaster, or another spray on product, on the three bolts connecting the ex. manifolds to the ex. pipes. Each side of the car. Do it a few days before starting , then do it every day until your ready to start. You will most likely need a long, long extension on the pass side of the car to get at the three bolts.

HAD2HAV2

Tool companies make a lot of different types of #40 torx sockets. You need at least 2 types.

cardo0

Block deck and head surfaces have to be squeaky clean. Use a non-abrasive synthetic wheel on a drill. Use a gasket with plenty of graphite in it. With 2 gasket failures now don't worry about quench this time - use a good thick quality gasket.

I wouldn't re-use the stock head bolts again - buy new (ARP). And use a torque wrench u trust it's cal.

Good luck.

mlm0

Good info. I've only had one gasket failure, so still use .051 gasket ? Will buy new bolts

dizwiz24

absolutely you need thread sealant on the head bolts (and you need new head bolts).

you also need thread chasers and brake parts cleaner the holes.

i razor-blade scraped and scotch brited the steel block deck - which i know someone will say is terrible to do, because you get abrasive aluminum oxide particles in the cylinder bore. as long as you dont get that mess into your cylinder, its a great idea to scotch brite the deck.

i avoided that issue by finding 4" diameter round cardboard lids that fit tight into the cylinders. i was careful to wipe out the cylinder bores, even using a shop vac around ring edges.

the last step is very important: be sure to pull out the knock sensors and drain the brake parts cleaner that you got into th coolant jacket !

cardo0

U need to do the shopping for your head gasket as u will have the details u need for it. Im saying a head gasket with graphite layers will do better w/alum heads because the alum head squirms around more than the iron block as they both heat up and cool down. I dont like the name of Multi-Layer-Steel (MLS) for alum heads but they do come with a lot of alum heads - even stock heads so i expect u can call them a composite gasket and may have enough graphite or graphite layers to work well.

So u have to do your own research here. First start w/what came with the heads. I think your heads are stock L98 correct? Was this a conversion from iron L98 heads? See i really dont know the details of your eng combo and afraid to make assumptions. I do know the iron deck for alum heads needs a much smoother finish/roughness than for iron heads (25Ra-30Ra Vs 50Ra-60Ra).

My point is quench is a lower priority now than a good sealing gasket. Look for a good gasket match and worry about a good quench height on another eng build.

Good luck and hope this helps.

Joe C

let me see if I've got this right - one gasket failure??? if i'm reading this right and understanding it, you are not planning on only replacing one side, are you? if so, (my 2-cents) .051"- BAD IDEA. pull both heads, SAME gasket thickness, both sides.

FWIW, personally, I always use new head bolts. my latest rebuild, I used ARP's with ARP sealant. (first time using ARP) - top quality stuff -

suggestion - as you clean the block deck, cleaning/scraping tool - one hand, shop vac, in your other. same with using thread chasers. keep everything clean as possible. in fact, I do a light pre-cleaning before I start the teardown.

bag, tag, and label EVERYTHING - do not rely on memory. digital pics a must.

VikingTrad3r

^^^^ the best advice so far. these jobs have certain "gotchas" that make an easy-ish job a nightmare. DONT break any bolts and or electrical plugs.

Dont rush or u will break stuff.

i just finished my job 2 weeks ago.

whatever snag u hit, we can all help.

my techniqe was to tak an old ceral box and a drill bit to put all manifold and head bolts in the correct pattern with numbers labelled. i used my brass wheel to clean all the threads.

i reused all bolts.

i used permatex aviation form a gasket on all threads. in the head. i used anti seize on the exhaust bolts.

for other paraphanalia and bolts, i bagged all similar bolts into a sanswhich ziploc and sharpie labelled.

i tied back the wires with a soft rope over the too of the car holding them back.

i could do another head gasket in 1 day easy.

I started mine on dec 9 and finished a couple weeks ago but that was casual whenever i had time and i learned every step for the first time as i went.

u will be great!

mlm0

No, I'm doing both