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Discussion Starter #1
Hi,

need to change the leaking exhaust manifold to head gaskets on the rear bank of my 1995 3.0 24v 164 Super.

Got new gaskets for both ends of the manifold ready but trying to find out two things before starting:

1) what needs to be undone to remove the manifold? False firewall out, etc?
2) can anyone recommend a thin-walled 13mm ring spanner that will get onto the nuts closest to the manifold pipes?

Thanks
 

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I've been there albeit a 12v engine but with 24v headers and 24v downpipes. No special tools required. You can do this w/o firewall removal, but plenum must be tilted up out of the way, then you'll do some nuts from top, some from bottom. It's tight and not a fun job. First drop the downpipes and disconnect them from the cat (easier said than done if your cat bolts are frozen!). That will create some space for you to get your arms in there. The manifold shield is a pain to remove; the removal of the starter wires will definitely be helpful too. Installing the new exhaust gaskets is a challenge without having them fall down, I used a little masking tape to hold them in place while getting the screws started (you can leave the tape there, it will just burn off).
 

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Discussion Starter #3
I've been there albeit a 12v engine but with 24v headers and 24v downpipes. No special tools required. You can do this w/o firewall removal, but plenum must be tilted up out of the way, then you'll do some nuts from top, some from bottom. It's tight and not a fun job. First drop the downpipes and disconnect them from the cat (easier said than done if your cat bolts are frozen!). That will create some space for you to get your arms in there. The manifold shield is a pain to remove; the removal of the starter wires will definitely be helpful too. Installing the new exhaust gaskets is a challenge without having them fall down, I used a little masking tape to hold them in place while getting the screws started (you can leave the tape there, it will just burn off).
Many thanks. Was hoping to escape having to get under the car but seems not.
Cat was changed two years ago so bolts hopefully not seized.

Cheers :)
 

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Two additional thoughts:

1) when you remove the manifold nuts at the head, very likely one or more of the studs will back off with the nut as a unit—adding another nuisance to the job. Then your choice is either to install them back the same way, or [preferably] , go to the trouble of separating the nuts from the studs, and re-installing the studs separately.

2) on reassembly always smear the studs/nuts with anti-seize compound.
 

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really small hands and an uncanny ability to twist your forearm / wrist into unnatural positions! some need to be attacked from the bottom
Get a 13mm offset open end wrench as well, take a regular 13mm box and grind it down as needed. its tricky to get in there.
as for gaskets, use a rubber band to hold em in place, one you get the nuts started cut the rubber band off and voila its all good

Anti seize everything and not too tight!
 

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Discussion Starter #6
Two additional thoughts:

1) when you remove the manifold nuts at the head, very likely one or more of the studs will back off with the nut as a unit—adding another nuisance to the job. Then your choice is either to install them back the same way, or [preferably] , go to the trouble of separating the nuts from the studs, and re-installing the studs separately.

2) on reassembly always smear the studs/nuts with anti-seize compound.
Thanks. Got anti-seize. Not expecting a stud to come out as undid these bolts two years ago, without putting in new gaskets as only backed off manifold rather than removing it. My mistake. Hence the issue now...
 

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Discussion Starter #7
really small hands and an uncanny ability to twist your forearm / wrist into unnatural positions! some need to be attacked from the bottom
Get a 13mm offset open end wrench as well, take a regular 13mm box and grind it down as needed. its tricky to get in there.
as for gaskets, use a rubber band to hold em in place, one you get the nuts started cut the rubber band off and voila its all good

Anti seize everything and not too tight!
Thanks Goats,

Going to take the plenum chamber completely off to minimise amount of stuff from below. Just bought thin-walled stubby ring/open-ended 13mm spanner to help.

Interesting rubber band idea.

Anti-seize ready and waiting.

Cheers :)
 

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Discussion Starter #8
Hi,
Got plenum chamber off today and can get fingers on most of the exhaust bolts. Wondering if taking the false firewall out will allow me to do everything from above.

Any thoughts anyone?
 

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That worked for me to remove FF-wall on Myron's LS. Still not easy and you may still have to take down pipes loose to get manifold to move enough to get gasket to slide over studs in head.
 

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Discussion Starter #10
That worked for me to remove FF-wall on Myron's LS. Still not easy and you may still have to take down pipes loose to get manifold to move enough to get gasket to slide over studs in head.
Steve, you are always such a star. Thank you! Will try without undoing downpipe but even if have to that's only 2 bolts which are easy enough to get to.

Great :)
 

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Not for me but admit I knew I was going below decks anyway-- so I left ff in place-- I don't think there is any way other than to remove the down pipes-- it's too cramped and everything tight unless u want to take off all exhaust hangers -- really it's not a terrible job but it's a dirty one
 

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Discussion Starter #12
Good news, job done!

What a dog! Took out false-firewall, plenum chamber and all major obstacles 'upstairs' but still had to get underneath to undo the downpipe.

All six manifold bolts were undone from above - took hours and have bruised backs of my hands from squeezing into tight gaps to prove it. Access for these bolts from below looked even worse; at least with the starter in the way - not removed this time.

Special note: Yes,one of my manifold gaskets had evidence of some leakage but once ready to get to the manifold nuts I noticed the EGR pipe was quite wobbly. In other words the banjo bolt connecting its bottom end to the manifold was loose - an exhaust leak in itself. I also discovered the gasket between the rear exhaust manifold and downpipe had broken up. It wasn't a proper solid steel gasket but a three-layer one, which came off in three parts. To be fair, am unsure if it was leaking or not.

Got a proper solid steel gasket on there now but, ironically, three-layer ones on the manifold to head joints. Right now they don't leak and am really please (and aching) but if I had solid gaskets to hand, like the originals I took out, I would have put them in instead.

One thing I do have to say, when you are working on your own car you take extra care not to damage to aged rubber hoses and such. If it was just a garage, even an Alfa one, it would be difficult for them to take such care even if they wanted to. They would be subject to criticism for taking too long and charging too much for the labour. So, while I still hurt like hell and felt like abandoning or at least short-cutting the job several times, I am still glad I took the decision to do it myself - not to mention being £400+ better off. But make no mistake this is not a job for the faint hearted or those without the right tools. If this is you, don't mess about with it, take it straight to someone like Alfisto Steve and just pick up the keys when it's done.

Thank you all for your advice. Hope I never need to do this again - ever!
 

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... What a dog!
... took hours and have bruised backs of my hands
... am really pleased (and aching)
... I still hurt like hell and felt like abandoning or at least short-cutting the job several times
... But make no mistake this is not a job for the faint hearted or those without the right tools.
We warned you! Steve, Goats and Pinino wrote:

... It's tight and not a fun job
... The manifold shield is a pain to remove
... Installing the new exhaust gaskets is a challenge without without having them fall down
... it's too cramped and everything tight
... really it's not a terrible job but it's a dirty one
... Still not easy and you may still have to take down pipes
... really small hands and an uncanny ability to twist your forearm / wrist into unnatural positions!
... very likely one or more of the studs will back off with the nut as a unit—adding another nuisance to the job

Anyway, we are glad it's over—and bet if you did the job again it would take 1/2 the time.
 

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Discussion Starter #14
We warned you! Steve, Goats and Pinino wrote:

... It's tight and not a fun job
... The manifold shield is a pain to remove
... Installing the new exhaust gaskets is a challenge without without having them fall down
... it's too cramped and everything tight
... really it's not a terrible job but it's a dirty one
... Still not easy and you may still have to take down pipes
... really small hands and an uncanny ability to twist your forearm / wrist into unnatural positions!
... very likely one or more of the studs will back off with the nut as a unit—adding another nuisance to the job

Anyway, we are glad it's over—and bet if you did the job again it would take 1/2 the time.
The next time I do this job I will be dropping the subframe for a total revamp and have it all removed ;-)

Cheers guys :)))
 

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Did you use the rubber band trick to hold the gaskets in place until you get the mani loosely attached?
 

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Discussion Starter #16
Did you use the rubber band trick to hold the gaskets in place until you get the mani loosely attached?
Hi,

I found the gaskets were such an exact fit they kept themselves in place until the manifold was mated up. Really happy about that, as well as getting the job done. :)
 
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