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exhaust manifold gasket replacement

2078 Views 7 Replies 5 Participants Last post by  zfanman

Could you please explain to me why the head need to be removed to replace the exhaust manifold gasket? I looked at Haynes manual and did not see anything about removing the head to repalce the exhaust manifold gasket. I am not that familier with this job and just need to understand the process better.

Your thoughts will be very much appreciated.

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i never heard or seen anybody take off the head to replace the exhaust manifold gasket, you should be able to get to all the bolts...i think actualy only intake manifold has to be taken off to get to the bolts, not sure on that tho...
I copied three previous posts below from members of this forum about how difficult it is to get to the exhaust manifold without taking the head off. I know it is difficult to do on the zx but I need to know more about the process.


Re: exhaust manifold leak repair
Author: steves280
Date: Oct 15, 6:13pm

The first guy has probably worked on an 82-83 before and knows what a BITCH it is to do with the head installed. The second guy thinks it's like an earlier car and is fixing to learn what the first guy already knows.

You -can- do it without removing the head but I'm not sure it's faster to do it that way. The later manifold is shaped where it a total PITA to get to the bolts. It's kinda a toss up which way to go time wise and getting a new head gasket isn't a bad thing. Don't be surprised if the second guy calls you back saying it isn't like he thought is was! Doing this gasket on a 75 280Z is easy, on an 82ZX it isn't.

Steve 77 280z, SDS w/turbo injectors, MSD, 276/.480cam, Sunbelt-intake, 621 header, shaved and shimmed P79 head w/ flat top pistons, susp mods, toyo calipers etc etc.. my engine

Re: exhaust manifold leak repair
Author: stonehenge69
Date: Oct 15, 6:30pm

Steve's right. I won't even consider changing out a intake/exhaust gasket on a later ZX without pulling the head. The head and both manifolds can be pulled in less than an hour. The manifolds can then be removed on a bench, reassembled and installed as a unit.

Re: exhaust manifold leak repair
Author: chiZguy
Date: Oct 15, 6:58pm

Steve and Stone are both right. I learned the hard way on a friend's 82zx, it was like death only worse. Besides, wouldn't it really suck to have guy #2 do the job and then blow the head gasket a week later?

'77 280Z: E88, Triple SK's, too much cam, header, and a WAY too big exhaust.

Post Edited (Nov 4, 8:48pm)
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oh i see theyr saying its way easier to take it off with the head off...

well I was gonna do it too but then i saw all the work that needed to go into it and decided to leave it untill i need to replace it.

well if you are gonn have.lots of time...
you gotta take apart the whole intake manifold...disconnect pretty much everything from it just so you can get it off...make sure you depressurise all the fuel lines and put rags wherever you can so if you get a small fuel leak it will pick it up...also there is coolant lines that will be in your way i think (look around) so make sure you got them cleaned out too so it doesnt leak out everywhere.... make sure you write/remmember where each hose and connection goes where..TAKE PICTURES. i didnt its a PITA.
so far my input....
don't be affraid, it's easy.. I had mine done in a couple of hours and I sure as heck didn't remove the head...
-start by depressurize the fuel system (remove relay and crank or strart Z and remove relay and let run till it dies works iether way)
-disconnect Bat.
- remove front idler pully and remove stud that holds the fuel rail to the front of the head and the one that hold the rail to the thermostate housing...
-take off the intake hose between AFM and throttle body
-oops allmost for got about the coolant lines.. there are a couple off coolant lins that go to a thingy under the air regulator disconnect these by the thermostate housing.. they don't leak much.
-remove 4 big bolts on intake..
-take the little screw out in the middle and remove inspection cover..
-loosen all manifold studs.. or at least all the big ones that hold the intake on...
- remove and mark the wiring and vacume lines.
-disconect throttle linkage,
Intake should slide up and you can leave the fuel lines connected or remove them and take the intake right out of the engine bay.. I just moved mine to the front on top of the air cleaner box... then the manifold and all the studs are visable.... unbolt them all... and with a little wiggling the manifold will come out and you can remove the old gasket and clean the surface. install the new gasket and reinstall everything else... gravy

Post Edited (Nov 4, 10:32pm)
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An 82 ISN'T the same as the earlier Z engines or a ZXT. They changed the exhaust manifold design and it's almost impossible to do this without removing the head. It -can- be done but it's MUCH easier on the last years of the ZX to pull the head to do this. Like I said on an earlier car or a turbo, it isn't a problem.
Me and a guy up in WA took the head and everything else attached to the block off in a few hours. None of it is "hard" work. The only "hard work" is if you do NOT take the head off in which case you spend hours on one bolt/ stud. The down side is you need to buy another head gasket and you have to be real careful as to not warp the head, scratch it etc.
Thank you all. I appreciate your help.
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